Formatting issues on MultipleSelect "alertOnChange": true

### Description of the bug

If their is a lot of selections in a MulitpleSelect component and a user wants to delete all of the selections (using `"alertOnChange": true` property) the buttons accept and cancel does not appear in the pop-up windowfield.

Windowfield should resize depending on text length of the selections or have a maximum text size that is displayed e.g. "Er du sikker på at du vil slette 01 Tørkemidler, 01 Valkemidl...?"

### Steps To Reproduce

1. Add a multipleSelect component with property `"alertOnChange" : true`
2. Make an appOptions List with a lot of options.
3. Add options to multipleSelect.
4. Press on "x" (delete)

### Additional Information

In addition the button "hide selectable options" in frontend, does'nt work (applies to both multipleSelect and dropdown and the components in designSystemet).

Start by reproducing the MultipleSelect flow with alertOnChange enabled and many selected options, then inspect the confirmation pop-up and the frontend “hide selectable options” behavior for MultipleSelect and dropdown. Done means the confirmation buttons remain usable with long selections and the hide-options button works in the reported components.

Written by the indexing model from the issue text.