Extend `Struct.field_set()` so that the `path` type can be a
`dna.FieldPath`, to mirror `Struct.field_get`'s `path` type, and allow
users to set file-block's subproperties. For example this allows
setting `object_block[(b'id', 'name')]`.
Also, along the way, added a test for getting subproperty value.
Reviewed-on: https://projects.blender.org/blender/blender-asset-tracer/pulls/92899
Add an `array_index` parameter to `block.get(property_name)` to get a
specific item from an array.
Example:
```python
verts = self.bf.block_from_addr[verts_ptr]
assert verts.get(b"co") == [-1.0, -1.0, -1.0] # index 0
assert verts.get(b"co", array_index=1) == [-1.0, -1.0, 1.0]
```
Reviewed-on: https://projects.blender.org/blender/blender-asset-tracer/pulls/92898
BlendFileBlock attributes:
Explicit annotation on BlendFileBlock are needed because otherwise
e.g. `block.add_old` type was imprecisely inferred from the
assignments as `int | Any`, where `Any` comes from `.unpack` returning
`tuple[Any, ...]`.
Ideally unpack should be somehow connected to the returned types, but
this solution should work for now just to avoid typing errors.
dna_io - add some missing annotations:
Some annotations were needed to ensure `block.code` will be inferred
as `bytes` and not `bytes | Unknown`.
Reviewed-on: https://projects.blender.org/blender/blender-asset-tracer/pulls/92897
Reviewed-by: Sybren A. Stüvel <sybren@blender.org>
Andrej730