fix(animation): properly update Web Animation, clean up types

[liamdebeasi]

⚠️ Add Manu as co-author when merging

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

progressEnd web animations were not being updated properly

What is the new behavior?

1. Ensure progressEnd updates Web Animations
2. Update types.
3. Reorganize code a bit

Does this introduce a breaking change?

• Yes
• No

Other information