Fixes T97706
Adds operator to duplicate the active color attribute layer.
Adds `"Color Attribute Specials"` menu to color attribute ui to access the `"geometry.color_attribute_duplicate"` operator.
Internally adds a function that duplicates a referenced CustomDataLayer
- `BKE_id_attribute_duplicate` mostly copies the existing `BKE_id_attribute_new`
- but gets the type and domain from the referenced layer
- and copies the data from the old layer into the new layer
Reviewed By: Joseph Eagar & Hans Goudey & Julien Kaspar
Differential Revision: https://developer.blender.org/D14823
Ref D14823
9c28f0eb37