Bounce commit files selection render to UI thread

The redraw of the selection color (using <space>) would be tied to the
spinner drawing. To reproduce, having a high spinner refresh rate and
toggling a file would see a delay equivalent to the time spinner refresh
rate.

pkg/gui/controllers/commits_files_controller.go

@@ -476,7 +476,11 @@ func (self *CommitFilesController) toggleForPatch(selectedNodes []*filetree.Comm
 				self.c.Git().Patch.PatchBuilder.Reset()
 			}
 
-			self.c.PostRefreshUpdate(self.context())
+			self.c.OnUIThread(func() error {
+				self.c.PostRefreshUpdate(self.context())
+				return nil
+			})
+
 			return nil
 		})
 	}