chore: improve dapr pubsub api

[seeflood]

Signed-off-by: seeflood zhou.qunli@foxmail.com

What this PR does:
improve dapr pubsub api
Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov]

Codecov Report

Merging #725 (9c5abef) into main (0e908fc) will increase coverage by 0.01%.
The diff coverage is 88.46%.

@@            Coverage Diff             @@
##             main     #725      +/-   ##
==========================================
+ Coverage   60.05%   60.06%   +0.01%     
==========================================
  Files         128      128              
  Lines        6766     6769       +3     
==========================================
+ Hits         4063     4066       +3     
  Misses       2311     2311              
  Partials      392      392              

Impacted Files	Coverage Δ
pkg/grpc/dapr/dapr_api.go	57.50% <ø> (-1.04%)	⬇️
pkg/grpc/dapr/dapr_api_pubsub.go	42.58% <88.46%> (+1.91%)	⬆️

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