Add a explorer context menu entry to let the user pick the profile they want to "open here"

[zadjii-msft]

Follow up from #6100

We should add another entry to the explorer context menu to let the user select which profile.

This is the only other option I'm considering at this time, I don't want to clutter that UI too badly.

notes:

• We could maybe allow arbitrary customization akin to what we're planning for Allow dropdown menu customization in profiles.json #1571.
• startupActions not working when launching Terminal from an explorer folder #9749, startupActions don't trigger on launching from context menu #11348: people want to use startupActions in the specified directory
• Proposal: Evolution of startingDirectory #9991 maybe also relevant