* BMP daemon: add EVPN route-monitor parsing and JSON fields - #918

Add a new BMP EVPN regression test with sanitized raw_msg hex samples covering route types 1-5, so parser-output invariants are validated deterministically without traffic replay.

Decode EVPN (type 0x06) and Encapsulation opaque communities with IANA
names and structured or hex value fields; unknown EVPN sub-types and other
unhandled tuples use hex instead of "?". BMP route-monitor uses the same
bgp_attr_parse_ecommunity path as BGP UPDATEs, so ecomms strings match.

Decode tunnel TLVs and sub-TLVs into a summary string (VXLAN/NVGRE VNI,
egress endpoint); expose as tunnel_encap in JSON msglog. Include attribute
in attr hash interning; fix BGP-LS attr parse fall-through to default.

Introduce config directive bmp_daemon_msglog_evpn_raw_msg (default false).
When enabled on BMP, unknown path attributes in UPDATE messages are collected
as tlv type plus hex payload (0x-prefixed, truncated at 4096 octets) and
emitted in EVPN JSON msglog as unknown-tlv array. Extend bgp_attr_parse with
bgp_msg_data context and bgp_peer_log_msg with optional bmd for JSON output.

Parse path attribute 22 (RFC 6514) into structured PMSI fields, emit them in JSON output, and include PMSI state in attribute lifecycle/hash paths so EVPN IMET updates are logged as decoded PMSI instead of unknown TLV blobs.

Parse RFC4577-compatible legacy EC types 0x8000 and 0x8001 into OSPF-RT and OSPF-RID display strings, and update 302/304 expected JSON fixtures to match the new decoded ecomms format.

This allows JSON msglog to emit parsed extended communities as ecomms_list objects and suppress legacy ecomms output unless explicitly disabled.

This makes ecomms_list emit singleton values for constrained ECs and arrays for repeatable ones while keeping 302/304 fixtures stable by explicitly disabling ecomms_list in their configs.