feat(modal): add ability to programmatically set current sheet breakpoint

[EinfachHans]

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?

Developers cannot programmatically move a sheet modal breakpoint with an API.

Issue Number: #23917

What is the new behavior?

• setCurrentBreakpoint(breakpoint: number) to programmatically change the breakpoint of a sheet modal.
• getBreakpoint() to get the active breakpoint value for a sheet modal.
• ionModalBreakpointWillChange/breakpointWillChange event when the breakpoint is about to change.
• ionModalBreakpointDidChange/breakpointDidChange event when the breakpoint changes.
• extract Code to animate the gesture to a specific breakpoint to be used for the new method and the existing usage of the gesture
• after this is merged feat: sheet style modal should change breakpoint on handle click #24069 is easy as well, i can create a PR for this as well

Does this introduce a breaking change?

• Yes
• No

Other information

[sean-perkins]

Have one suggested change for the public API naming for setting the breakpoint value.

Reviewed most of the changes here and they align with our internal feature design document. I would like to introduce a set of e2e tests on this new behavior, mainly to verify correct event emission and a few screenshot tests. I'll clone your fork this week and experiment with your changes to verify everything works correctly and will suggest a few tests on the new behavior.

Thanks for the great work here!

[EinfachHans]

@sean-perkins Changes applied 😊

[sean-perkins]

We are getting close! Had one question.

I need to sync with the team tomorrow, trying to figure out the best way to test/validate a breakpoint is transitioned to correctly. Currently added coverage for events emitting/breakpoint values being set correctly.

Also due to the way we overwrite the implementation of ion-modal in Angular, I need to add a small set of e2e tests to our Angular test app to validate event emissions. I should be able to finish this piece tonight.

[amandaejohnston]

This LGTM once those two comments are addressed 👍

[liamdebeasi]

Good to merge once my other two comments are addressed.

Great job @EinfachHans and @sean-perkins! This is a great feature addition to Ionic.