UCP/UCT/UCS: Add memory registration flags (#11553)

* UCP/UCT/UCS: Add memory registration flags

Add memory flags to UCS memory information and propagate them through UCT mem_query_v2 so providers can report whether a memory region is safe to register.

Use the CAN_REGISTER flag in UCP memory registration and protocol selection paths to avoid selecting registration-dependent protocols for non-registerable memory. Mark CUDA async allocations classified as CUDA managed as non-registerable, and require CAN_REGISTER for IB memory domains that need registration.

Add focused gtests for memtype cache flag handling, IB registration failure for CUDA async memory, and UCP protocol filtering.