glvdebug: Improve replay highlighting of api calls on stop / finish.

glvdebug: Improve replay highlighting of api calls on stop / finish.

* Fix a bug where the 'play to here' context menu option was not working correctly if a proxy model was used on the treeView.
* Reset the 'play to here' indicator after the api call is reached, otherwise subsequent 'play' would continue to pause on the 'play to here' call.
* Previously there was a sense of incompletion when the replay finished because the tree view would not update to reflect the new location. The treeView now highlights the final API call when the replay is finished.
* Previously when the replay was stopped, the treeView was not updated to a new location. Since stopping the replay also resets it back to the beginning of the trace, the first API call is now selected.
* Pausing continues to select the API call that was paused on.