Do not filter to remote branches only

[schacon]

Way back in November, we reverted functionality where we would list local branches in addition to remote branches in our sidebar. It makes sense, we want to be able to convert local branches to virtual branches. But due to naming confusion, the branches have been restricted to remote branches ever since.

This PR is exploring what we need minimally to revert this back to listing all branches that you can turn into virtual branches.

• filter out gitbutler/integration
• filter out remote branches that are already fully contained in any virtual branch head

[krlvi]

Consider renaming the command or alternatively I can do it in a new PR

[schacon]

I'm mainly just pushing up my notes to make sure you see them, but we need to decide if we want to refactor all the code around "remote" branches or just get something minimal working and address it later. Now all the Typescript code has been renamed to RemoteBranch (it used to be the more generic BranchData), the Rust structs are all "RemoteX", there's Remote stuff all over the place, when they all meant "normal git branch" for a while.

But now I'm seeing some other bugs in applying remote branches that are also issues converting local branches into virtual branches, so I'm going down the rabbit hole of figuring out why that is exactly.