Move files from Frontend directory to pcsx2 and/or subdirectories.
Get rid of double GS init.
Combine HostSettings and Host.
Combine Frontend/Achievements.h and Achievements.h.
GS/DX11: Don't throw bad_alloc on surface creation fail
GS: Link device and host display construction/destruction
FullscreenUI: Replace HostDisplayTexture with GSTexture
GS: Purge HostDisplayTexture
GS: Move everything in HostDisplay to GSDevice
GS: Move ImGui rendering to GSDevice
GS: Get rid of reset/store API state