TerraNexus Additions

Fixes:

• Fixed an additional sign with an incorrect texture
• Adjusted rendering
• The hotkey for the marking tool was always saved and triggered later
• Markings disappear completely if a block is removed from underneath them or if the space next to a block that the marking borders on consists of air
• Road sign issue

New:

• Added missing corner clinker brick facades
• Added garage door blocks (one function is currently still missing)

Planned:

• Garage door blocks with doors that also have a door function
• Build road signs on top of one another for combined signs