Rating support for WD Tagger

[Disty0]

• Add rating support for WD Tagger.
  Inserts rating tag as the first tag.
• Reorder character tags to be in front of the general tags.
  Characters can get lost into the token limit if it is at the end.
  AnimagineXL also uses this order.

Also decided to squeeze in support for pin_memory for IPEX in this PR.

[sdbds]

Suggest inserting character tags in front as well

[kohya-ss]

Thank you for this. This seems to be good. However I wonder an additional option to enable this feature will be needed, because this is a breaking change.

[Disty0]

Added --use_rating_tags and --character_tags_first.

Also did some formatting changes for arg parser part for consistency and did a few small changes over the code to make ruff happy.
These shouldn't have any affect for the functionality.

[kohya-ss]

Several features have been added to further comply with the Animagine format. Documentation has also been added. I'd be happy if you will check them out.

cae5aa0

[Disty0]

I like the option --character_tag_expand and will use it on my dataset.

[kohya-ss]

Without your PR I would not have come up with these features. Thank you!