tests(coverage): Increase middleware tests coverage

[darkweak]

Description (what this PR does / why we need it):

github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:56:                   WithSigningMethod       100.0%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:65:                   WithClaims              100.0%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:72:                   WithTokenHeader         100.0%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:79:                   Server                  87.5%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:134:                  Client                  91.3%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:172:                  NewContext              100.0%
github.com/go-kratos/kratos/v2/middleware/auth/jwt/jwt.go:177:                  FromContext             100.0%
github.com/go-kratos/kratos/v2/middleware/circuitbreaker/circuitbreaker.go:22:  WithGroup               100.0%
github.com/go-kratos/kratos/v2/middleware/circuitbreaker/circuitbreaker.go:34:  Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/logging/logging.go:15:                Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/logging/logging.go:51:                Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/logging/logging.go:87:                extractArgs             100.0%
github.com/go-kratos/kratos/v2/middleware/logging/logging.go:95:                extractError            100.0%
github.com/go-kratos/kratos/v2/middleware/metadata/metadata.go:20:              hasPrefix               100.0%
github.com/go-kratos/kratos/v2/middleware/metadata/metadata.go:31:              WithConstants           100.0%
github.com/go-kratos/kratos/v2/middleware/metadata/metadata.go:38:              WithPropagatedPrefix    100.0%
github.com/go-kratos/kratos/v2/middleware/metadata/metadata.go:45:              Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/metadata/metadata.go:70:              Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/metrics/metrics.go:18:                WithRequests            100.0%
github.com/go-kratos/kratos/v2/middleware/metrics/metrics.go:25:                WithSeconds             100.0%
github.com/go-kratos/kratos/v2/middleware/metrics/metrics.go:39:                Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/metrics/metrics.go:74:                Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/middleware.go:14:                     Chain                   100.0%
github.com/go-kratos/kratos/v2/middleware/ratelimit/ratelimit.go:20:            WithLimiter             100.0%
github.com/go-kratos/kratos/v2/middleware/ratelimit/ratelimit.go:31:            Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/recovery/recovery.go:26:              WithHandler             100.0%
github.com/go-kratos/kratos/v2/middleware/recovery/recovery.go:34:              WithLogger              100.0%
github.com/go-kratos/kratos/v2/middleware/recovery/recovery.go:39:              Recovery                100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:41:              Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:46:              Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:51:              Prefix                  100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:57:              Regex                   100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:63:              Path                    100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:69:              Match                   100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:75:              Build                   100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:86:              matches                 100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:119:             selector                100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:130:             pathMatch               100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:134:             prefixMatch             100.0%
github.com/go-kratos/kratos/v2/middleware/selector/selector.go:138:             regexMatch              100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/metadata.go:19:               Inject                  100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/metadata.go:27:               Extract                 100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/metadata.go:43:               Fields                  100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/span.go:20:                   setClientSpan           100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/span.go:57:                   setServerSpan           100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/span.go:100:                  parseFullMethod         100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/span.go:119:                  peerAttr                100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/span.go:135:                  parseTarget             100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/statsHandler.go:16:           HandleConn              100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/statsHandler.go:21:           TagConn                 100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/statsHandler.go:26:           HandleRPC               100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/statsHandler.go:41:           TagRPC                  100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracer.go:24:                 NewTracer               100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracer.go:46:                 Start                   100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracer.go:61:                 End                     100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:23:                WithPropagator          100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:31:                WithTracerProvider      100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:38:                Server                  100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:54:                Client                  100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:70:                TraceID                 100.0%
github.com/go-kratos/kratos/v2/middleware/tracing/tracing.go:80:                SpanID                  100.0%
github.com/go-kratos/kratos/v2/middleware/validate/validate.go:15:              Validator               100.0%
total:                                                                          (statements)            98.6%

I am not able to improve the jwt.go Client/Server coverage.

Which issue(s) this PR fixes (resolves / be part of):

Part of #2147
Middlewares coverage improvements

Other special notes for the reviewers:

[daemon365]

Please fix lint error, use make fix.

[codecov-commenter]

Codecov Report

Merging #2165 (6296294) into main (20b7c9f) will increase coverage by 3.11%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2165      +/-   ##
==========================================
+ Coverage   79.03%   82.14%   +3.11%     
==========================================
  Files          84       86       +2     
  Lines        3696     3741      +45     
==========================================
+ Hits         2921     3073     +152     
+ Misses        562      480      -82     
+ Partials      213      188      -25     

Impacted Files	Coverage Δ
middleware/tracing/statsHandler.go	100.00% <100.00%> (+100.00%)	⬆️
encoding/form/proto_encode.go	71.32% <0.00%> (-0.42%)	⬇️
middleware/circuitbreaker/circuitbreaker.go	100.00% <0.00%> (ø)
middleware/ratelimit/ratelimit.go	100.00% <0.00%> (ø)
internal/context/context.go	100.00% <0.00%> (+2.98%)	⬆️
middleware/logging/logging.go	100.00% <0.00%> (+3.03%)	⬆️
middleware/recovery/recovery.go	95.45% <0.00%> (+4.54%)	⬆️
middleware/metadata/metadata.go	100.00% <0.00%> (+6.52%)	⬆️
middleware/selector/selector.go	100.00% <0.00%> (+6.66%)	⬆️
middleware/tracing/metadata.go	100.00% <0.00%> (+11.76%)	⬆️
... and 5 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 20b7c9f...6296294. Read the comment docs.

[daemon365]

LGTM