Handle use of bpy.types.AnyType

[Mysteryem]

AnyType is used by functions that accept any Blender pointer type, since it only extends bpy_struct, PyCharm's type checking will complain whenever we're trying to normally use functions that have an AnyType parameter.

If AnyType is strictly a leftover from before bpy.type.bpy_struct was accessible then it could be replaced in all cases where it's used.

Another possibility might be inserting AnyType into the class hierarchy such that all pointer types (all bpy_struct types?) become subclasses of AnyType.

[Mysteryem]

Another alternative: since AnyType declares no attributes, functions or properties (other than bl_rna), the class definitions for AnyType could be replaced with an alias of AnyType = bpy.types.bpy_struct. This would remove it as a distinct class from the documentation however, which might not be the best idea for documentation purposes.