test: add coreboot boot log checks

[Spina7]

Summary

• Adds coreboot base-port checks for common boot-log issues:
  • ASSERTION ERROR
  • missing static PCI devices (not found, disabling it.)
  • resource allocation failures (Resource didn't fit!!!)
  • BUG: messages
  • Check your devicetree.cb warnings
• Adds a BASE_PORT_LOG_CHECK_SUPPORT flag, defaulting to false and enabled for QEMU.
• Adds shared Robot keywords to boot Ubuntu, switch to root, collect cbmem -1, and assert that forbidden boot-log patterns are absent.

Closes #921

Verification

• git diff --check
• static content assertions for all new CBP test IDs and forbidden patterns
• Robot parser check with TestSuiteBuilder().build('dasharo-compatibility/coreboot-base-port.robot')
• python scripts/ci/test_ids/test_ids_legal.py id-valid --print-invalid
• python scripts/ci/test_ids/test_ids_legal.py os-valid --print-invalid

Note: I could not run the full QEMU/Robot boot flow in this environment because it requires a complete OSFV testbed.