Notably:
* `Packed*Array.size()` and `Array.size()`.
* Shared methods of `Transform2D` and `Transform3D`.
* Shared methods of `Vector2`, `Vector3`, and `Vector2i`.
This reduces the Deja Vu when translating the class reference :)
- Back to 1-based layer names to make it clearer in editor UI
- Layer bit accessors are renamed to layer value and 1-based too
- Uniform errors and documentation in render and physics
- Fix a few remaining collision_layer used in place of collision_mask
For the time being we don't support writing a description for those, preferring
having all details in the method's description.
Using self-closing tags saves half the lines, and prevents contributors from
thinking that they should write the argument or return documentation there.
