TileMap: Add method to fetch the layer for a given body

[Proggle]

Currently it isn't possible to find the tilemap layer of what object you're colliding with. This adds a tilemap method, get_layer_for_body_rid(), which works just like the already-existing get_coords_for_body_rid(), except it returns the tilemap layer instead of the tilemap coordinates.

Bugsquad edit:

• Closes Add a method to return the TileMap layer a given RID is on, as well as the X/Y coordinates godot-proposals#6716

[groud]

Needs the commits to be squashed. Looks good otherwise.

[Proggle]

Needs the commits to be squashed. Looks good otherwise.

Sorry to ask, but can someone better with Git squash that for me? Something is screwy with git on my computer, I spent an hour talking with the helpful people in godot development chat trying to run commands and it keeps refusing to work.

I could make a new branch from scratch with the changes, but from what I understand that would also produce a new pull request rather than merging into this one.

[akien-mga]

Needs the commits to be squashed. Looks good otherwise.

Sorry to ask, but can someone better with Git squash that for me? Something is screwy with git on my computer, I spent an hour talking with the helpful people in godot development chat trying to run commands and it keeps refusing to work.

No problem, I squashed the commits for you :)

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉