feat(refresher): add ionEnd event

[WhatsThatItsPat]

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?

Issue Number:
#24524

What is the new behavior?

This adds an ionEnd event as an obverse to the ionStart event.

Does this introduce a breaking change?

• Yes
• No

Other information

This PR appears to work for the web, but I'm not sure if more has to be done for the native refreshers. There are a couple of comments that can be cleaned up after clarification on this.

[ShaneK]

Thanks for your PR! I have a PR to implement this with a few changes (mostly around naming conventions, old vs new), but I've given you co-author credit on the commit:
#30946

This is planned to go out in v8.8