Refactor the changes introduced in
https://github.com/zed-industries/zed/pull/50525, in order to remove the
`DisplayMap.clear_folded_buffer` method and update the editor's handling
of `multi_buffer::Event::ExcerptsRemoved` to actually call
`DisplayMap.unfold_buffers`, which correctly updates the `BlockMap`
using its `BlockMapWriter`, ensuring that the block map is synced.
Before you mark this PR as ready for review, make sure that you have:
- [X] Added a solid test coverage and/or screenshots from doing manual
testing
- [X] Done a self-review taking into account security and performance
aspects
- [X] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
Release Notes:
- N/A