Added:
- FCVAR_ACCESSIBLE_FROM_THREADS [1<<25]
- FCVAR_STUDIO_SYSTEM [1<<26]
- FCVAR_SERVER_FRAME_THREAD [1<<27]
- FCVAR_PLATFORM_SYSTEM [1<<31]
This commit also removes the 'FCVAR_MATERIAL_THREAD_MASK' from the ConVarFlags class (which is a helper struct for displaying flags on the developer console), as this is a mask and would therefore be marked as such in case a single bit in the mask matches, and all these bits are already added to the list.