Grid Combine Game's to-do list

[tinchodias]

• Fix domain bug (failing test)
• Another pass OOP on domain
• Simplify game element
• Color tiles
• Add UI tests
• Skins
  • Create a version without skin (and bloc-pac queries)
  • Add another skin to have more than one usage example
• Use a non-default font for tiles (to enrich the game as example)
• Add a separated score dashboard (instead of using the window title to show score)
• Add an announcement-free UI, as an alternative architecture to think on
• Scroll event bursts: find a better solution than isSlideEnabled for a prefixed duration
• Create home menu where a catalog of game modes are listed, and remember best scores of each mode
• Deploy standalone

[tinchodias]

• Separate games to other repo, e.g. pharo-graphics/games