refactor: improve hardware back button types (#28335)

Issue number: Internal

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## What is the current behavior?
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As part of FW-2832, the team would like to swap out usages of the `any`
type for stronger types.

## What is the new behavior?
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this PR. -->

- Added `ionBackButton` event types to the browser utilities
- Updated menuController to use the `doc` utility instead of `document`
so we can get proper types
- Moved the definitions for back button types out of `interface.d.ts`
and into `hardware-back-button`. `interface.d.ts` still exports these
back button interfaces.
- Updated all `BackButtonEvent` imports inside of `@ionic/core` to
import from the utility file instead of the public interface file.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

Note: This PR was separated from other type updates associated with the
FW-3832 work because I had to modify the implementation of a feature in
Ionic. While I don't expect there to be any functional differences, I
have opted to pull this work out into a separate branch and target a
feature branch to a) reduce the impact of any unintended bugs and b)
make it easier to do a `git bisect` if a bug is introduced.