Two bugs in SMSG_MESSAGECHAT parser for MONSTER_SAY/YELL/EMOTE:
1. Sender name included trailing null byte from server (nameLen includes
null terminator). The embedded null in std::string caused ImGui to
truncate the concatenated display string at the NPC name, hiding
" says: <message>" entirely.
2. Missing NamedGuid receiver name for non-player/non-pet targets. When
the receiver GUID is a creature, the server writes an additional
SizedCString (target name) that we weren't reading, shifting all
subsequent field reads.
Also adds MONSTER_WHISPER, MONSTER_PARTY, RAID_BOSS_EMOTE, RAID_BOSS_WHISPER
chat types with proper parsing and display formatting (says/yells/whispers).
b948720ec3