.git folder parser alternative without external dependencies

[tonyredondo]

This PR replace the dependency to src-d/go-git using a custom .git folder parser without any external dependencies.

[drodriguezhdez]

Can we include some tests?

[tonyredondo]

Can we include some tests?

I'll try, it's hard because reads the .git folder, but I guess I can do some tests of the regexes in use, at least...

[tonyredondo]

Can we include some tests?

Done @drodriguezhdez

[drodriguezhdez]

Checked with go-ethereum.
It seems branch is not being sending:

https://app.scope.dev/dashboard/b774c8da-2494-4ede-8d2f-b0321ff3cd7c/f9775d86-9c81-43d9-a28c-3f3cb60f30b4/default/explore/inspect/fe9cb4954f12ec9709d448d6f274c7088322eb60/00000000-0000-0000-70b3-e3e4509d0ff2/trace?spanId=00000000-0000-0000-0713-8c606cc58d21

[tonyredondo]

Checked with go-ethereum.
It seems branch is not being sending:

https://app.scope.dev/dashboard/b774c8da-2494-4ede-8d2f-b0321ff3cd7c/f9775d86-9c81-43d9-a28c-3f3cb60f30b4/default/explore/inspect/fe9cb4954f12ec9709d448d6f274c7088322eb60/00000000-0000-0000-70b3-e3e4509d0ff2/trace?spanId=00000000-0000-0000-0713-8c606cc58d21

Done, the branch = HEAD when a detached commit is being used was missing.

[drodriguezhdez]

Tested in local, with repos no containers, and with repos inside containers.
https://app.scope.dev/dashboard/b774c8da-2494-4ede-8d2f-b0321ff3cd7c/400412c1-517f-4f94-8291-7cc167d92ca4/default/explore/inspect/93645c357bde143c6275b6119fd255a8e8071287/00000000-0000-0000-69b2-30adb11f0355/trace?spanId=00000000-0000-0000-480d-57aa489125bb

Approved