Very minor CSS cleanup.
Merge branch 'sceneModeWidget' into imageryWidget

Conflicts:
	Source/Widgets/SceneModePicker/SceneModePicker.css
Add OpenStreetMap as a default available imagery provider

1. Also add more information to tooltips.
2. Set width to accommodate 3 items and a scrollbar
3. Set max height to accommodate 2 rows (line line labels) without scrolling.