This mirrors the C++ attribute API better, separates the implementation
of attributes from CustomData slightly, and makes functions simpler,
clearer, and safer.
Also fix an issue with removing an attribute caused by 97712b018d
meant the first attribute with the given type was removed instead of
the attribute with the given name.
If a geometry does not have CustomData for a certain domain,
it may still have CustomData on other domains. In that case
we need to continue to the other domains instead of returning.
This worked for meshes because the domains are all at the
start of the `info` array. It didn't work for curves.
This function only checked for uniqueness in the current domain,
while attribute names should be unique among all domains within
a geometry.
Differential Revision: https://developer.blender.org/D15144
This commit hides "UI attributes" described in T97452 from the UI lists
in mesh, curve, and point cloud properties, and disallow accessing them
in geometry nodes.
Internal UI attributes like selection and hiding values should use the
attribute system for simplicity and performance, but we don't want to
expose those attributes in the attribute panel, which is meant for
regular user interaction. Procedural access may be misleading or cause
problems, as described in the design task above.
These attributes are added by two upcoming patches: D14934, D14685
Differential Revision: https://developer.blender.org/D15069
