fix(tinymce): Do not exceed height of element window

[tvdeyen]

What is this pull request for?

Tinymce fullscreen height is broken in Chrome, because it has a calculated height.
Also use the correct colors for the overflowing toolbar.

Checklist

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.48%. Comparing base (5b7cea5) to head (1035dc3).
⚠️ Report is 15 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3642   +/-   ##
=======================================
  Coverage   97.48%   97.48%           
=======================================
  Files         314      314           
  Lines        8272     8272           
=======================================
  Hits         8064     8064           
  Misses        208      208           

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[alchemycms-bot]

💚 All backports created successfully

Status	Branch	Result
✅	8.0-stable
✅	8.1-stable

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details