Show numbers on attack damage and final strength comparison for battles

Changed Windows icon for Unciv to new icon

Unit icons no longer overlap unit action images, improved render time for unit images

MoveTo image visible

AbsoluteUnits - Unique Triremes - By letstalkaboutdune

By vegeta1k95:
- Modding: allow custom ResourcePortraits
- Fix foreign units flags fading
- Fix AI being able to bombard non-visible tiles + optimizations