Blender Git Loki

Fix T91461: Pose Library name filter not working

since `AssetHandle` does not have a `name_property`
(`RNA_def_struct_name_property`), and the UIList is just using the
default `uilist_filter_items_default` it simply cannot filter on names
(`RNA_struct_name_get_alloc` wont succeed).

Adding a name_property also wont work since `AssetHandle` inherits
`PropertyGroup` (which already sets name_property).

So this adds a (temporary) hack exception for RNA_AssetHandle in
uilist_filter_items_default until the design of `AssetHandle` progresses
further.

thx @Severin for additional feedback

Maniphest Tasks: T91461

Differential Revision: https://developer.blender.org/D12541