Tidy up indicators in collab panel (#8214)

Move away from columns of icons towards the "changed" info dot we used
for files.

Secondary actions for chat/notes still show up (if you're lucky) on
hover.

Co-Authored-By: Marshall <marshall@zed.dev>



Release Notes:

- Improved design of collab panel

---------

Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

script/bootstrap

@@ -10,11 +10,11 @@ mkdir -p .blob_store/the-extensions-bucket
 echo "creating database..."
 script/sqlx database create
 
-echo "migrating database..."
-(cd crates/collab && cargo run -- migrate)
+# echo "migrating database..."
+# cargo run -p collab -- migrate
 
 echo "seeding database..."
 script/seed-db
 
-echo "Linux dependencies..."
-script/linux
+# echo "Linux dependencies..."
+# script/linux