Added opcodes & handlers for 5.3.0:

- CMSG_MESSAGECHAT_AFK
- CMSG_MESSAGECHAT_CHANNEL
- CMSG_MESSAGECHAT_DND
- CMSG_MESSAGECHAT_EMOTE
- CMSG_MESSAGECHAT_GUILD
- CMSG_MESSAGECHAT_INSTANCE
- CMSG_MESSAGECHAT_OFFICER
- CMSG_MESSAGECHAT_PARTY
- CMSG_MESSAGECHAT_RAID
- CMSG_MESSAGECHAT_RAID_WARNING
- CMSG_MESSAGECHAT_SAY
- CMSG_MESSAGECHAT_WHISPER
- CMSG_MESSAGECHAT_YELL
- CMSG_SAVE_CUF_PROFILES
- SMSG_LOAD_CUF_PROFILES
- SMSG_LOG_XPGAIN
- SMSG_SET_PHASE_SHIFT
- SMSG_TITLE_EARNED
- SMSG_TITLE_REMOVED
- SMSG_TRADE_STATUS