feat: add onFocusIn, onFocusOut, onEscape callback props

[mxschll]

Description

• This PR refactors adds onFocusIn, onFocusIn, onEscape event handlers to the Dropdown component
• Renames onDropdownClose to onOutsideClick

See proposal RGJgABPXohP8 for more context.

How has this been tested?

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.35%. Comparing base (87a3e47) to head (413dba5).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4259   +/-   ##
=======================================
  Coverage   97.35%   97.35%           
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  Files         888      889    +1     
  Lines       26031    26057   +26     
  Branches     9411     9420    +9     
=======================================
+ Hits        25343    25369   +26     
- Misses        641      682   +41     
+ Partials       47        6   -41     

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[pan-kot]

Should we also include onEscape - like we have in the tooltip component?

Alternatively, we can parametrise onDropdownClose e.g. with some reason: "click-outside" | "escape".

[mxschll]

I can go with onEscape since it matches the tooltips API.

[pan-kot]

Why do we need this check?

[mxschll]

Internally we use onBlur which fires any time an element inside the dropdown content looses focus. So we check if the focus actually leaves the dropdown.