RDMA Executor support

[mustafabar]

Added

1. Support for RDMA-based data transfers in TransferBench. This executor enables data transfers using RDMA-capable NICs, bypassing host involvement for GPU/CPU transfers
2. Two new executor symbols are added: I and N. Nj is the nearest NIC to GPUj. Ij is NIC with index j.
3. Memory is preregistered so that the cost of registration is not included in the transfer
4. Added topology display support using PCIe tree mapping algorithm
5. Multi-port NIC mapping support so that GPUs that share a PCIe bridge with a GPU are evenly distributed on the ports
6. QPs are expressed as the number of sub-executors per transfer. Data is split over the QPs
7. Automatic GID Index detection for RoCE traffic (Code extracted from recent NCCL support)
8. When topology detection is not accurate, especially in systems with front NICs and multiport NICs, the CLOSEST_NIC variable can override the automatically detected topology