New Module: Gitdumper

[domwhewell-sage]

This PR adds a module git-dumper to recursively download leaked .git repos.

The request #1707 was originally for githacker but after some testing I couldn't get githacker to work even stand alone on the portswigger lab. (And seems gitdumper has been updated more recently)

The git module has been modified so it raises the discovered git folder as CODE_REPOSITORY -> the gitdumper module will then run the git_dumper library against it and raise a FILESYSTEM event with the usual git tag etc.

The git_dumper library sends it output to sys.stdout by default not sure if the run_in_executor can take an alternate stdout so that we get those messages in self.debug or alike

[domwhewell-sage]

This might be a dependency conflict
AttributeError: cffi library '_openssl' has no function, constant or global variable named 'Cryptography_HAS_ED448'

If it is there is a rust rewrite of git-dumper available which could be used instead

[TheTechromancer]

Relevant: #578

[domwhewell-sage]

DOH I completely forgot about that one!

I'll close this PR and open a new one written specifically for bbot