Support allow-listing by git link prefix

[jgpaiva]

Is your feature request related to a problem? Please describe.
My org heavily depends on git dependencies. Using licenses.private, I can set ignore = true and use registries = ["my-registry"] to ignore all dependencies from a specific registry, but I couldn't find a way to do the same for a specific git repo. I found I can do ignore-sources = ["git+ssh://git@bitbucket.myorg.com/team1/repo1git", "git+ssh://git@bitbucket.myorg.com/team1/repo2git"], but that's very tedious for our large projects and causes frequent breakage.

Describe the solution you'd like
In an ideal world, I'd be able to specify something like ignore-git = [ "git+ssh://git@bitbucket.myorg.com" ] and everything from that source would be ignored.

Describe alternatives you've considered
The only alternative I could find was to explicitly name very single transitive internal dependency of my project, and keep that list up-to-date as it changes upstream.