feat: add controller proxy for vsctl communication

[wenfengwang]

What problem does this PR solve?

Issue Number: close #110

Problem Summary:

In the implementation of before, we hard code controller information in vsctl codebase, the PR introduce controller proxy to resolve this problem.

What is changed and how it works?

use https://github.com/mwitkow/grpc-proxy as the reverse proxy to transport all grpc requests from vsctl to leader.

but due to https://github.com/mwitkow/grpc-proxy seems long time not maintaining, and the project have bug of mwitkow/grpc-proxy#62, I have to fork it and take that PR's changes to our fork: https://github.com/linkall-labs/grpc-proxy .

Check List

Tests

• Unit test

• Integration test

• Manual test (add detailed scripts or steps below)
  The vsctl has been tested paas based this PR

• No code

[codecov]

Codecov Report

Merging #117 (09a90b0) into main (5bb2f51) will increase coverage by 0.23%.
The diff coverage is 61.31%.

@@            Coverage Diff             @@
##             main     #117      +/-   ##
==========================================
+ Coverage   47.81%   48.05%   +0.23%     
==========================================
  Files          99      100       +1     
  Lines        8256     8391     +135     
==========================================
+ Hits         3948     4032      +84     
- Misses       4014     4052      +38     
- Partials      294      307      +13     

Impacted Files	Coverage Δ
internal/controller/eventbus/controller.go	0.00% <0.00%> (ø)
internal/gateway/gateway.go	0.00% <0.00%> (ø)
internal/gateway/grpc_proxy.go	63.15% <63.15%> (ø)

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[wenfengwang]

@xdlbdy I created the issue #119 for tracing the problem you appointed.