MSA Client ID has been moved to CMakeLists.txt, and defaults to the
Client ID for the PolyMC application.
Removed secrets/notsecrets library, replace with (temporary?)
program_info subdirectory.
This makes the account system much more modular
and makes it treat errors as something recoverable,
unless they come directly from the MSA refresh token
becoming invalid.
This makes the tokens not expire when such errors happen.
Only applies to MSA, not the XBox and Mojang steps afterwards.
Further testing and improvements are still needed.