Make sure actors are removed from control groups when captured

Fixes #5976.
Introduce RangeCircleRenderable.
Split selectable rendering into *Renderables.
Add UISpriteRenderable for screen-space decorations.
Change IPostRenderSelection and IPlaceBuildingDecoration to return renderables.
Change IOrderGenerator.RenderAfterWorld to return Renderables.
Merge pull request #6040 from pchote/more-renderables

Convert RenderAfterWorld to use Renderables.
Fix mouse event filtering in BackgroundWidget.
Allow ImageWidget to filter mouse events.
Fix mouseover filtering in cloned widgets.
Hide invalid hotkey from button tooltips.
Move TD production widgets into the RA project.
Don’t crash if there are no production icons. Fixes #5543.
Extract ProductionPalette background drawing into logic code.
Add support for single-line time display.
Split the last TD UI logic into reuseable chunks.
Unify cheats -> debug and adjust plumbing for new RA UI.
Make the diplomacy panel consistent with cheats and menu.
Support fading the area behind the radar to black.
Blink the power display red when low power.