Compare Batch API

[ajlende]

Description

Diff against a commit prior to the batch image editor API changes from WordPress#23284. For easier diff viewing for WordPress#23369. This diff only includes the API changes since the JavaScript changes don't cleanly apply, so it'll be missing the JavaScript changes from the original PR. All comments should go on WordPress#23369.

How has this been tested?

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.