Add full-duplex mode to NTTTCP networking workload

Enable bidirectional network testing where both nodes run sender and receiver
simultaneously, producing separate TX/RX throughput metrics per direction.

Core changes:
- NTttcpExecutor: Add DuplexMode property, ExecuteFullDuplexWorkloadAsync with
  parallel sender+receiver processes, CaptureDirectionalMetrics for per-direction
  telemetry, role-aware port assignment (forward/reverse), direction-aware -m IP
  mapping for correct sender→receiver targeting
- NetworkingWorkloadState: Add DuplexMode property for client-server state sync
- NetworkingWorkloadExecutor: Pass DuplexMode through orchestration instructions

Profile:
- PERF-NETWORK-NTTTCP-FULLDUPLEX.json: 6 TCP scenarios (T1/T32 x 4K/64K/256K)
  with DuplexMode=Full, same dependencies as half-duplex profile

Tests (21 tests):
- NTttcpFullDuplexTests: IsFullDuplex property, ReversePort offset, command-line
  flag/port/buffer verification for both platforms, execution tests for client
  send+receive on Linux/Windows, results file separation, half-duplex backward
  compatibility, NetworkingWorkloadState serialization with DuplexMode

Upstream fixes (pre-existing bugs in main):
- ProcessProxy.cs: Fix catch clause ordering (general catch before specific)
- CommandBase.cs: Fix NullReferenceException on isolationTargets.TargetPackages

Verified on real hardware: win-x64 (10.177.236.133) <-> win-arm64 (10.199.102.112)
TCP 4K T1: Send 3226 Mbps / Receive 1455 Mbps
TCP 64K T1: Send 6490 Mbps / Receive 6163 Mbps

Author: Rudra Pratap SIngh