[Premake] Removed unused/unnecessary subprojects.
- Testing currently doesn't work
- VFS Dump is unused. You can use internal function for it
- Demos are only for fun
- Trace Dump & Trace Viewer (unsure, but ok)
You can re-enable them by changing values: enableTests and enableMiscSubprojects in main premake file.
In the future there should be xb command support to overwrite them