Fix Auto folded dirs performance issues

[ABckh]

Fixed auto folded dirs which caused significant performance issues #8476 (#7674)

Moved from iterating over snapshot entries to use child_entries function from worktree.rs by making it public

@maxbrunsfeld

Release Notes:

• Fixed a bug where project panel settings changes would not be applied immediately.
• Added a project_panel.auto_fold_dirs setting which collapses the nesting in the project panel when there is a chain of folders containing a single folder.

[mikayla-maki]

Let's fix the issue in is_foldable and get this up to date with main, then we can merge it :)

[MrTact]

Are there render tests anywhere such that we could add tests with pathologically long folded directory hierarchies, so we can monitor this for regressions?

[mikayla-maki]

Thanks for fixing those issues @ABckh!

I did some manual testing, and things are feeling smooth when switching tabs. I'm going to merge without the caching we where discussing earlier and see how it feels.

That said, I also defaulted this new setting to false, as it seems to mainly be useful for Java.