LDtk map support

[Dandielo]

Implement an asset Oven for the LDtk editor tile map format. This editor is a nice replacement for Tiled at some point and should be good enough to provide initial support for it.

The format documentation: https://ldtk.io/docs/game-dev/loading-ldtk-in-your-game/

What we would like to have:

• Loading of all defined tile sets
• Loading of single level from the tile map
• Loading all layers from that level
• (Optional) Loading of collision objects, if possible
• (Optional) Loading of all available levels, if possible