Add an option to change border colors

[theactualmariluski]

Description of the new feature

Add an option to change border colors
I had this idea of making so you can change the border colors.

This is specially usefull when you have multiple windows and you dont want to use a terminal multiplexer.

Proposed technical implementation details

I don't know if the way VSCode is made and the Window terminal nad if they are a bit compatible.
There is a VSCode extension called peacock that changes border colors

[zadjii-msft]

xlinking for my own sake:

https://www.peacockcode.dev/

Looks a lot like different Themes.

#9818 has a note about previewing different themes (though, I don't think it's tracked anywhere specific?)

then there's also the idea of per-window themes (which would be enabled by #9992)

then there's also "workspaces" which I'm tracking in #17084, which would allow a similar idea of setting global settings on a window name and you can save that window name. Kinda would also play into this.

There's also already $theme.$window.frame for controlling the window border

[zadjii-msft]

So, just for my own notekeeping - would an action that lets you switch between themes be sufficient here?