Fix: context menu is visible even when selection is collapsed (#2116)

* Fix: context menu is visible even when selection is collapse

* Chore: dart fixes

* Fix: context menu fails by null value when try to update the view

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Co-authored-by: CatHood0 <santiagowmar@gmail.com>

lib/src/editor/raw_editor/raw_editor_state.dart

@@ -1419,7 +1419,10 @@ class QuillRawEditorState extends EditorState
 
   void _updateOrDisposeSelectionOverlayIfNeeded() {
     if (_selectionOverlay != null) {
-      if (_hasFocus) {
+      if (!_hasFocus || textEditingValue.selection.isCollapsed) {
+        _selectionOverlay?.dispose();
+        _selectionOverlay = null;
+      } else if (_hasFocus) {
         _selectionOverlay!.update(textEditingValue);
       }
     } else if (_hasFocus) {