Passive AXI4 protocol checker on the monitor modport. On top of the
per-channel handshake-stability rules it enforces burst legality:
WLAST/RLAST aligning with AxLEN, bursts staying inside a 4 KiB page,
legal AxBURST/AxSIZE. It tracks responses per ID, so it accepts
interleaved out-of-order reads and out-of-order write responses, and
flags a BID/RID with no outstanding request. Exclusive transactions
(AxLOCK) must be power-of-two, ≤ 16 beats, ≤ 128 bytes and size-aligned,
and EXOKAY may only answer an exclusive access.