Fix for keyboard jumping when switching focus from a TextField (singerdmx#1810)

Author: oligazar

lib/src/widgets/raw_editor/raw_editor_state.dart

@@ -1453,6 +1453,7 @@ class QuillRawEditorState extends EditorState
 
   void _handleFocusChanged() {
     if (dirty) {
+      requestKeyboard();
       SchedulerBinding.instance
           .addPostFrameCallback((_) => _handleFocusChanged());
       return;