[tests] Fix OSM unit test on Mac
Fix for #8860, overlap of Close drop-down menu button on message bar

- Make tool button menu pop indicator a separate single-click button
Fix for #8860, (followup 65200e3)

- Hide background of tool button's menu button on Ubuntu
Fix for #8874, right-clicking on message in message bar shows black background for context menu
fix set image no data, fixes #8773
Don't draw mouse handles in composition outputs (fix #8879)