Add support for TileMap pattern rendering

[Zehir]

Add support for TileMap pattern rendering

Summary

This PR adds support for a new Type in TileMapGaeaMaterial, enabling tiles to be rendered using TileMap patterns defined in the TileSet.

The Pattern material have 2 options;

• pattern_index; Pattern index in the pattern list of the [TileSet].
• pattern_offset; Pattern offset use to shift the tiles from the origin (Top left corner of the pattern).
  The offset is a quick ajustement for the pattern placement because by default the patten will be placed from the top left of the pattern.

Also I placed pattern after everything because he will update multiples cell at once.

I did not update the demo scene but I tried it and works correctly

[cullumi]

Looks to get the job done, thanks for adding this to 2.0 @Zehir !