This MR implements group affinity support in attributes list passed to CreateRemoteThreadEx().
(up to the current Wine limit of 64 logical cores).
It also adds a couple of missing APIs definitions related to group affinity support.
Notes: - duplicating for the Nth time struct _PROC_THREAD_ATTRIBUTE_LIST definition isn't very nice... perhaps we should define it somewhere? - it's very likely that CreateRemoteThreadEx() should call into NtCreateThreadEx() (instead of the Rtl counter part), but I opted for the simpler approach to set thread affinity after thread creation (this could be changed if needed).
-- v3: kernelbase: Support group affinity attributes. kernel32/tests: Test thread creation with group affinity attributes. include: Add missing process group related definitions. kernelbase: Support affinity group in process/thread attributes list. kernel32: Test adding group affinity to proc/thread attributes list.