This commit adds a new Nexus test that implements the test
specification in test-1-4-PIC-TC-1.md. The test verifies Border
Router functionality including:
- DHCPv6-PD client to obtain OMR prefix
- Advertising route to OMR prefix on AIL (Stub Router)
- DNS recursive resolver for public internet addresses
- Connectivity (ICMPv6, UDP, TCP/HTTP) to internet and local servers
New files:
- tests/nexus/test_1_4_PIC_TC_1.cpp: C++ test execution
- tests/nexus/verify_1_4_PIC_TC_1.py: Python pcap verification
Nexus platform enhancements:
- Enabled DHCPv6-PD client in openthread-core-nexus-config.h
- Implemented DHCPv6-PD platform APIs in nexus_infra_if.cpp
- Added RDNSS option to RA in nexus_infra_if.cpp
- Improved packet delivery on infrastructure interface in nexus_core.cpp
- Fixed upstream DNS query matching in nexus_dns.cpp
Jonathan Hui