feat: support etcd authentication

[PowderLi]

issue: #28895
add 3 configuration for ETCD config

[codecov]

Codecov Report

Attention: 17 lines in your changes are missing coverage. Please review.

Comparison is base (4637659) 83.19% compared to head (0ebff01) 83.14%.
Report is 7 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #30226      +/-   ##
==========================================
- Coverage   83.19%   83.14%   -0.05%     
==========================================
  Files         701      701              
  Lines      113124   113209      +85     
==========================================
+ Hits        94108    94131      +23     
- Misses      15405    15450      +45     
- Partials     3611     3628      +17     

Files	Coverage Δ
internal/distributed/datacoord/service.go	87.85% <100.00%> (+0.14%)	⬆️
internal/distributed/datanode/service.go	79.38% <100.00%> (+0.27%)	⬆️
internal/distributed/indexnode/service.go	71.34% <100.00%> (-1.96%)	⬇️
internal/distributed/proxy/service.go	82.91% <100.00%> (-0.60%)	⬇️
internal/distributed/querycoord/service.go	74.67% <100.00%> (+0.33%)	⬆️
internal/distributed/querynode/service.go	80.48% <100.00%> (+0.28%)	⬆️
internal/distributed/rootcoord/service.go	80.07% <100.00%> (+0.21%)	⬆️
internal/kv/etcd/metakv_factory.go	70.73% <100.00%> (+2.31%)	⬆️
internal/util/dependency/kv/kv_client_handler.go	89.18% <100.00%> (+0.95%)	⬆️
pkg/config/etcd_source.go	81.05% <100.00%> (+11.57%)	⬆️
... and 5 more

... and 21 files with indirect coverage changes

[xiaofan-luan]

/lgtm
/approve

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: PowderLi, xiaofan-luan

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