Add missing workspace edit capabilities (zed-industries#6950)

Closes zed-industries#6916

Specification:
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspaceEdit
Adds a safe minimum of the capabilities that Zed supports already,
allowing rust-analyzer to send file edits on rename.

Release Notes:

- Fixed rust module rename from editor not renaming the FS entries
([6916](zed-industries#6916))

zed 0.120.3

zed 0.119.20

collab 0.42.0

zed 0.120.2

zed 0.119.19

collab 0.41.0

zed 0.120.1

Revert "Ensure that notify observations are sent during `Window::draw…

…()`" (zed-industries#6152)

Reverts zed-industries#4236

This causes an infinite loop when opening the language server logs

zed 0.119.18