feat(refresher): add ionEnd event

[WhatsThatItsPat]

Pull request checklist

Please check if your PR fulfills the following requirements:

• [x] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been reviewed and added / updated if needed (for bug fixes / features)
• [x] Build (npm run build) was run locally and any changes were pushed
• [x] 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
• [x] 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: https://github.com/ionic-team/ionic-framework/issues/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
• [x] 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.