SUI Nullable Colors & Icon control Follow-ups

[carlos-zamora]

Follow-ups from #17870:

• [x] [A11y] Screen readers don't read expander's preview text
  • Tracked in https://github.com/microsoft/microsoft-ui-xaml/issues/10282
  • ~Hmm... it might be better to just directly set the AutomationProperty.Name~
  • PR #18418
• [x] Add Tab Color to settings UI
  • PR #19351
• [ ] Update CursorColor preview to display #FFFFFF as "invert"
• [X] Use Leonard's font picker UI, with the Segoe icon picker, so that you can filter the list
  • PR #19569
• [ ] [High contrast] we should probably add borders to the color chip previews

From Bug bash 1/21

• [ ] [Windows 10] Conflicting Windows & app theme causes this:

• [x] [Windows 10] Checkmark icon is missing!

• [x] Narrow window = cut off

• [ ] When using an emoji for the Profile icon, I run into this while using certain emojis (shield) though that might just be an issue with the emoji itself (not our problem?)

[malik-n]

[ ] When using an emoji for the Profile icon, I run into this while using certain emojis (shield) though that might just be an issue with the emoji itself (not our problem?)

I am also experiencing this bug. Even though I have not tried different emojis yet. I am using 🖥️