Add local override for git dependency

Description

Feature request, and couldn't find any related issues.

Would it be possible to add support for git dependencies to the paket.local override file?

I have a core repository and multiple dependant applications. The dependent apps use a git dependency to the core's public repository. While developing, I would like to use my local core repository instead of the public repository.

E.g.
paket.dependencies

git https://github.com/forki/AskMe.git 97ee5ae7074b

paket.local

git https://github.com/forki/AskMe.git -> git file:///c:/my/local/path.git

paket.local seems like the right place for this, because it shouldn't change the lock file, and restore is the most convenient timing for it to update from the local repository.

Known workarounds

I'm currently working around this by using paket.local, but think I'm being blocked by #3116.
It feels like I could technically do by having a fake nuget reference, which I replace with my local repository

nuget MyPackage -> git file:///c:/my/local/path.git Packages: /bin/

and add a reference to /paket-files/localfilesystem/..., but that seems very hacky.

Start by tracing how paket.local is read during restore, using the paket.dependencies and paket.local examples in the issue as the expected inputs. Check how Git dependencies are resolved and how the lock file is handled. Done means a local Git repository can override the matching dependency during restore without changing the lock file.