Inhibit clipping when dropdown is opened

[kazcw]

Pull Request Description

Fixes #9379.

Important Notes

• The existence-registry could be implemented with a counter, but a set is more debuggable and the performance cost is negligible.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed, the GUI was tested when built using ./run ide build.

[enso-bot]

Keziah Wesley reports a new STANDUP for today (2024-03-14):

Progress: Fixed dropdown clipping. Implemented conditional ports. It should be finished by 2024-03-15.

Next Day: Next day I will be working on the #9434 task. Start on multiselect

[farmaazon]

Is it the only place which may clip drop-down? Could node clip the leftmost drop-down?

[kazcw]

This prevents the clipping required by the hidden-placeholders animation from interfering with the dropdown. I don't think we have any other animations that could clip the dropdown, but if we do this solution could be applied to them. If any widget is enabling clipping on its children statically, that would be a separate problem with a different solution (the widget must not do that).

[farmaazon]

And one more thing: please add documentation explaining why do we have those clipping inhibitors.