- `bpy_struct.id_data` - provide a type.
- `bpy_struct` - add missing return types to
`bpy_struct.get`, `bpy_struct.pop`, `bpy_struct.path_resolve`.
- `bpy_struct` - add missing argument types to some methods.
- `bpy_struct` - provide explicit `/` and `*` in signatures to make it
clear which arguments are positional / keyword-only.
Ref !141334