Blender Git Loki

Geometry Nodes: initial attribute list for meshes

This adds a new Attributes panel in the mesh properties editor.
It shows a list of all the generic attributes on the mesh.
In the future, we want to show built-in and other attributes in the
list as well. Related technical design tasks: T88460, T89054.

There is also a new simple name collision check that warns the user
when there are multiple attributes with the same name. This can be
problematic when the attribute is supposed to be used in geometry
nodes or during rendering.

Differential Revision: https://developer.blender.org/D11276