Loft arguments out of kwargs

[ssteinbach]

• Lofting the arguments out of kwargs and into the function signatures makes it easier to discover what controls are available to the adapter
• because otiopluginfo uses reflection to discover arguments, non-kwargs arguments will show up in the output of otiopluginfo if they are lofted out:

❯ otiopluginfo AAF -p adapters
Manifests loaded:
  ~/workspace/otio-aaf-adapter/src/otio_aaf_adapter/plugin_manifest.json
  ~/opt/miniconda3/envs/otio.test.py38/lib/python3.8/site-packages/opentimelineio/adapters/builtin_adapters.plugin_manifest.json

adapters:
  AAF
    doc (short): OpenTimelineIO Advanced Authoring Format (AAF) Adapter
    path: ~/Documents/workspace/otio-aaf-adapter/src/otio_aaf_adapter/adapters/advanced_authoring_format.py
    from manifest: ~/Documents/workspace/otio-aaf-adapter/src/otio_aaf_adapter/plugin_manifest.json
    explicit supported features:
      read_from_file args: ['filepath', 'simplify', 'transcribe_log', 'attach_markers', 'bake_keyframed_properties']
      write_to_file args: ['input_otio', 'filepath', 'prefer_file_mob_id', 'use_empty_mob_ids']