lint: make include guard check pass for BGL headers

[RYB-404]

Description

Fixes the include-guard lint so it can run cleanly on the current Bitgesell tree and catches real BGL header mismatches instead of failing on imported/generated headers.

The current test/lint/lint-include-guards.py exits non-zero on the repository as-is. Some failures are external or generated headers that intentionally keep upstream guard names, while several BGL-owned headers have small guard/comment mismatches. This makes the lint noisy and less useful for reviewers.

What changed

• Excluded generated/imported headers from the include-guard lint where enforcing the BGL naming convention would be inappropriate.
• Fixed BGL-owned include guard mismatches in:
  • src/chainparamsseeds.h
  • src/consensus/amount.h
  • src/kernel/mempool_persist.h
  • src/policy/feerate.h
  • src/test/scriptnum10.h
  • src/util/readwritefile.h
  • src/util/trace.h
  • src/zmq/zmqrpc.h

Verification

• python test/lint/lint-include-guards.py
• python -m py_compile test/lint/lint-include-guards.py
• git diff --check

I could not run the Rust test/lint/test_runner wrapper locally because cargo is not installed in this environment, but the underlying include-guard linter passes directly.

/claim #39