Add types PointZ, PointM and PointZM

[Kabie]

I'm not sure I did it right on type = Utils.hex_to_type(type &&& 0xdf_ff_ff_ff).

[bryanjos]

@Kabie looks good! For you concern on type = Utils.hex_to_type(type &&& 0xdf_ff_ff_ff), I'm guessing it's fine since all the tests pass. This project was one of my first in Elixir so there are probably a lot of things specifically in that area that could have been done better.

If all is good I can merge it. Saw the "WIP" earlier and didn't know if you were finished or not

[bryanjos]

I learned something from this PR. I thought that making the coordinate values tuples would allow them to be used for more than just 2D coordinates. I never encountered Z, M, or ZM before and now I see why they have to be different types because could be some ambiguity between Z and M geometries.

[Kabie]

Thanks. My first thought was to reuse Geo.Point but not succeed.

I think it's finished now, feel free to merge it.