Work in progress changes & commits get (optionally) imported during project add

[krlvi]

We used to have the functionality where during the process of adding a repo, if there was work in progress, it was added as a virtual branch, which no longer works.

Lets bring it back in an optional way. If a developer has selected origin/main as their target and they are currently on foo with 2 commits and 3 uncommitted changes, present that and ask the developer if they wish to have that added as a virtual branch.

[Byron]

Probably related to #3048.