Move worktree tests into their own file (#2608)

The worktree has a lot of tests. Let's reduce their indentation, and
make it easier to navigate to them. We deserve it.

Just doing this in its own PR, to minimize conflicts.

Release Notes:

- N/A
77367bf2e4Max Brunsfeld committed on 6/13/2023, 5:50:49 PM· committed by GitHubparentsb272db95b6d1a2
3 files changedLine totals unavailable