Add a way to filter items in the outline panel (#13984)

https://github.com/zed-industries/zed/assets/2690773/145a7cf2-332c-46c9-ab2f-42a77504f54f

Adds a way to filter entries in the outline panel, by showing all
entries (even if their parents were collapsed) that fuzzy match a given
query.

Release Notes:

- Added a way to filter items in the outline panel
9b688655a8Kirill Bulatov committed on 7/9/2024, 1:44:24 PM· committed by GitHubparent9a6f30f
7 files changedLine totals unavailable