message: fix char position updating with gUU and guu
diff: @@ -2082,7 +2082,7 @@ export class UpperCaseOperator extends BaseOperator {
  await TextEditor.replace(range, text.toUpperCase());
  vimState.currentMode = ModeName.Normal;
  - vimState.cursorPosition = vimState.cursorPositionJustBeforeAnythingHappened[0];
  + vimState.cursorPosition = start;
  return vimState;
  }
  @@ -2106,7 +2106,7 @@ export class LowerCaseOperator extends BaseOperator {
  await TextEditor.replace(range, text.toLowerCase());
  vimState.currentMode = ModeName.Normal;
  - vimState.cursorPosition = vimState.cursorPositionJustBeforeAnythingHappened[0];
  + vimState.cursorPosition = start;
  return vimState;
  }
  