This PR adds a sample monarch/peasant application. This is a type of
application where a single "Monarch" can coordinate the actions of multiple
other "Peasant" processes, as described by the specs in #7240 and #8135.
This project is intended to be a standalone sample of how the architecture would
work, without involving the entirety of the Windows Terminal build. Eventually,
this architecture will be incorporated into `wt.exe` itself, to enable scenarios
like:
* Run `wt` in the current window (#4472)
* Single Instance Mode (#2227)
For an example of this sample running, see the below GIF:
This sample operates largely by printing to the console, to help the reader
understand how it's working through its logic.
I'm doing this mostly so we can have a _committed_ sample of this type of application, kinda like how VtPipeTerm is a sample ConPTY application. It's a lot easier to understand (& build on) when there aren't any window shenanigans, settings loading, Island instantiation, or anything else that the whole of `WindowsTerminal.exe` needs
* [x] I work here
* [x] This is sample code, so I'm not shipping tests for it.
* [x] Go see the doc over in #8135
c33a97955f
