Add hci_transaction_tracer and the hci-tracer comparison utility

[FrancescoConti]

Add a purely passive, simulation-only monitor that observes an HCI-Core stream through the monitor modport of an hci_core_intf interface and appends every transaction to a JSON log file. HCI-Core being bidirectional, two logs are produced, named by the REQ_LOG_FILE and RSP_LOG_FILE parameters: accepted requests (req & gnt) and consumed responses (r_valid & r_ready). Side channels are logged only when their width parameter is non-zero. The body of the module sits inside an ifndef SYNTHESIS guard, so the tracer can be instantiated unconditionally and elaborates to an empty module under synthesis.

Each log is a single well-formed JSON document, closed by a final block, and follows one of the new hci_transaction_request-v1 / hci_transaction_response-v1 JSON schemas in tracer/.

tracer/ also holds hci-tracer, a Rust utility that compares such logs:

hci-tracer hci-vs-hci --a-req F --a-rsp F --b-req F --b-rsp F
hci-tracer hci-req-vs-stream --hci F --stream F
hci-tracer hci-rsp-vs-stream --hci F --stream F
hci-tracer stream-vs-stream --a F --b F

Comparison runs on the content of valid data only, never on the time of a transaction: seq and cycle are reported so a difference can be found in a waveform, but they are structurally excluded from the comparison keys. Byte enables are canonicalized to bit-level masks before being compared, so be and strb encodings with different granularities compare equal when they enable the same data bits, and bytes neither side considers meaningful are don't-care.

The two sequences are aligned with Myers' algorithm, so an inserted transaction is reported as an insertion instead of cascading into a mismatch for every transaction after it. Output is hexadecimal, with only the differing nibbles painted red, a caret row when colour is off, wide values folded into 64-bit rows, and a summary table per section. Logs cut short by an aborted simulation are repaired automatically.

Includes unit tests for every module and integration tests over synthetic logs in tracer/tests/fixtures/, regenerated by gen_fixtures.py.

[FrancescoConti]

Depends on pulp-platform/hwpe-stream#35