feat: support request body rewrite #127

[TomCN0803]

Features and modifications includes:

• Update github.com/api7/ext-plugin-proto to v0.6.1
• Add SetBody([]byte) to http.Request
• Add a sample request body rewrite plugin
• Add an e2e test for the sample request body rewrite plugin
• Lint some code and add items (e.g. .vscode, go.work) to .gitignore

[codecov-commenter]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (f049304) 80.75% compared to head (b5bf984) 80.37%.

:exclamation: Current head b5bf984 differs from pull request most recent head f23ac95. Consider uploading reports for the commit f23ac95 to get more accurate results

Files	Patch %	Lines
cmd/go-runner/plugins/request_body_rewrite.go	75.00%	2 Missing and 2 partials :warning:
internal/http/request.go	90.90%	0 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #151 +/- ## ========================================== - Coverage 80.75% 80.37% -0.38% ========================================== Files 16 17 +1 Lines 1034 1060 +26 ========================================== + Hits 835 852 +17 - Misses 146 156 +10 + Partials 53 52 -1 ```

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[monkeyDluffy6017]

Nice work!

[monkeyDluffy6017]

@bzp2010 please help to review

[soulbird]

Whether content-length needs to be processed？

[TomCN0803]

Whether content-length needs to be processed？

@soulbird Is it a must to make limitations here? Flatbuffer itself has size limit of 2GB (https://stackoverflow.com/questions/59185516/do-flatbuffers-have-size-limits).