Added background to CommandKeyChord

[RickleAndMortimer]

Summary of the Pull Request

Adds a background to key chord border in the CommandPalette Screen. This prevents certain accent colors from rendering the KeyChords unreadable.

Before (where the text is unreadble);

After (from this PR):

See #15228 for more details

Closes #15228

[lhecker]

While this is an acceptable solution, why can't we make the border and text within black, similar to how "Close pane" turns from white to black when being hovered?

[RickleAndMortimer]

This was the approach that was suggested here #15228 (comment)

Note

Walkthrough

Probably the easiest way to do this would be to just add a .Background() to this border:

terminal/src/cascadia/TerminalApp/CommandPalette.xaml

Lines 73 to 79 in ca5834e

	<Border Grid.Column="2"
	Padding="2,0,2,0"
	HorizontalAlignment="Right"
	VerticalAlignment="Center"
	AutomationProperties.AccessibilityView="Raw"
	Style="{ThemeResource KeyChordBorderStyle}"
	Visibility="{x:Bind Item.KeyChordText, Mode=OneWay, Converter={StaticResource CommandKeyChordVisibilityConverter}}">

and use like, the CommandPalette background there, so that it appears transparent, but actually isn't.
(this was an off the cuff suggestion during triage, and we all thought it was a good idea)

I can definitely take a look at coloring the borders and text black instead, looks like a good idea as well 👍

[zadjii-msft]

Honestly, I'm cool with this as-is. If you can figure out how to get it to match the other text, be my guest, but this alone is still an improvement.

[lhecker]

It's a ✅ for me as well, but I'll wait a little bit just in case you happen to have time to check if it can be done with the color change, just because I think it would look better / more consistent. But I'd definitely also approve it without such a change.

[RickleAndMortimer]

Not sure if I can find a clean approach in changing colors based on the theme. This is good to merge 👍 as is

[DHowett]

Thanks for the contribution! 😄