Mapping update: copy and paste and rotate selection

[snipercup]

This requires #67 to work. I will publish this PR as a draft to make sure #67 gets merged first.

• fixes a bug in the selection of tiles using rectangle select
• Updates the Generichouse.json map so it has 4 houses instead of 2
• Adds sidewalk and concrete tiles to paint with
• You can copy and paste tiles using buttons in the toolbar. There is one to copy the current level and another to copy all levels
• Some buttons now have working hotkeys. Hover over the button and it will show in ( ) symbols what key is the hotkey
• The selection of tiles can be rotated, even across levels. Now we can copy, rotate and paste an entire house
• Some refactoring of the mapeditor
• Fixed the position of the brush preview
• Only one button that manipulates a selection or paints a rectangle can be active at any time

2024-02-11.02-31-01.mp4