🌱 Initial implementation of go-git client

[azeemshaikh38]

What kind of change does this PR introduce?

Initial implementation of RepoClient APIs using go-git. Note that this is not an implementation of RepoClient interface, but rather a handler to replace tarballHandler. Part of #1709.

(Is it a bug fix, feature, docs update, something else?)

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What is the current behavior?

What is the new behavior (if this is a feature change)?**

• Tests for the changes have been added (for bug fixes/features)

Which issue(s) this PR fixes

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[codecov]

Codecov Report

Merging #2720 (116a057) into main (c20ed9e) will decrease coverage by 0.41%.
The diff coverage is 0.78%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2720      +/-   ##
==========================================
- Coverage   49.91%   49.51%   -0.41%     
==========================================
  Files         156      157       +1     
  Lines       11669    11795     +126     
==========================================
+ Hits         5825     5840      +15     
- Misses       5490     5601     +111     
  Partials      354      354              

[spencerschrock]

Looks good for initial implementation. Some small nits