Menu: Fix floating directive performance issues

[Tannex]

Which issue does this PR close?

This PR closes #3351

What is the new behavior?

Floating directive now only updates host element position manually when:

• Setting strategy when floating element is shown
• Setting placement when floating element is shown

Additionally, autoUpdate is enabled only on show, and disabled on hide / destroy.

For now, autoUpdate (from floating-ui) also performs an initial update. If this is changed in the future, tests are added to catch it.

Update: Now also re-enables autoUpdate if reference changes while floating element is shown.

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

No breaking changes unless users hacked into private functions / fields somehow.

Are there any additional context?

Performance profiling from cookbook menu page.

Before changes:

[video] https://github.com/kirbydesign/designsystem/assets/5255948/118ecc7c-8239-4c45-8764-36f31a7716d4

After changes:

[video] https://github.com/kirbydesign/designsystem/assets/5255948/4cebc73e-acc0-4bfd-83db-0f4f0b62bb8e

Checklist:

The following tasks should be carried out in sequence in order to follow the process of contributing correctly.

Reminders

• [x] Make sure you have implemented tests following the guidelines in: "The good: Test".
• [ ] Make sure you have updated the cookbook with examples and showcases (for bug fixes, enhancements & new components).

Review

• [x] Determine if your changes are a fix, feature or breaking-change, and add the matching label to your PR. If it is tooling, dependency updates or similar, add ignore-for-release.
• [x] Do a self-review.
• [x] Request that the changes are code-reviewed
• [ ] Request that the changes are UX reviewed (only necessary if your PR introduces visual changes)

When the pull request has been approved it will be merged to develop by Team Kirby.