Correction of dropdown menu styles in CKEditor 5

Problem/Motivation

Coverage of some styles from the → module is missing. The most troublesome are the deficiencies for the dark mode, so the ones I found I fixed that.

Steps to reproduce

1. Instal CKEditor 5 Plugin Pack module
2. Configure Color picker or other tool with dropdown
3. Before changes:
4. Even numeric list dropdown has the same problem:

I made a patch to fix some issues