This allows us to make Content.Client and Content.Server Exe projects so that they can be executed directly via your IDE. This'll help wtih not forgetting to do a full rebuild and such.
They no longer load system-wide config or user data.
User data is emulated through a VFS.
Also added more hooks to improve the customizability of the test,
for example allowing content to hijack their IoC registrations.
* Server works if not connected to a tty.
* Rich presence does not run IoC resolution at runtime anymore.
* Work towards integration tests.
Mostly work related to making it so the server and client can run in
parallel, and allowing more control over main loop for testing.
* Lots of code relating to integration tests.