Rework point data management

[Failxxx]

Description

I don't think we need to have different ways to import point data as vertex colors (remap options).
Indeed, we could simply use the 'Map Range' node remap values.

Links to documentation, examples or class definitions

Here is an example:
Left, use of the 'Map Range' node with a 'LOCAL' method for remapping, with values [-0.3978, 0.3978].
Right, 'CUSTOM' method for remapping [0.1, 0.3].
This difference is probably due to a first remap operation when using 'LOCAL' method (see next screenshot).

Pseudocode or screenshots

Totally remove the 'method' option?

[Failxxx]

Also, vertex_colors is deprecated since 3.2. Would probably be nice to use color_attributes now.
See:

• https://docs.blender.org/api/current/bpy.types.Mesh.html?highlight=mesh#bpy.types.Mesh.vertex_colors
• https://wiki.blender.org/wiki/Reference/Release_Notes/3.2/Python_API

[Failxxx]

However, it does not seem possible to store point data which values are not in [0, 1] as the documentation says: https://docs.blender.org/api/3.1/bpy.types.MeshLoopColor.html#bpy.types.MeshLoopColor

Thus, it could be difficult to implement this for Blender versions < 3.2