Fix Helix mode search & selection (#42928)

This PR redoes the desired behavior changes of #41583 (reverted in
#42892) but less invasively

Closes #41125
Closes #41164

Release Notes:

- N/A

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/editor/src/editor.rs

@@ -1099,7 +1099,7 @@ pub struct Editor {
     searchable: bool,
     cursor_shape: CursorShape,
     current_line_highlight: Option<CurrentLineHighlight>,
-    collapse_matches: bool,
+    pub collapse_matches: bool,
     autoindent_mode: Option<AutoindentMode>,
     workspace: Option<(WeakEntity<Workspace>, Option<WorkspaceId>)>,
     input_enabled: bool,