When the cursor type changes mark it dirty but don't force it to redraw...

When the cursor type changes mark it dirty but don't force it to redraw immediately. This caused performance issues for tmux users. A comment in issue 4976

sources/PTYTextView.m

@@ -625,8 +625,7 @@ static const int kDragThreshold = 3;
 - (void)setCursorType:(ITermCursorType)value {
     _drawingHelper.cursorType = value;
-    [self setCursorNeedsDisplay];
-    [self refresh];
+    [self markCursorDirty];
 }
 - (NSDictionary*)markedTextAttributes {
@@ -1042,10 +1041,10 @@ static const int kDragThreshold = 3;
 }
 - (void)markCursorDirty {
-  int currentCursorX = [_dataSource cursorX] - 1;
-  int currentCursorY = [_dataSource cursorY] - 1;
+    int currentCursorX = [_dataSource cursorX] - 1;
+    int currentCursorY = [_dataSource cursorY] - 1;
     DLog(@"Mark cursor position %d, %d dirty.", currentCursorX, currentCursorY);
-  [_dataSource setCharDirtyAtCursorX:currentCursorX Y:currentCursorY];
+    [_dataSource setCharDirtyAtCursorX:currentCursorX Y:currentCursorY];
 }
 - (void)setCursorVisible:(BOOL)cursorVisible {