[3072] Rename UNIT_BYTE1_FLAG_UNK_2 to UNIT_BYTE1_FLAG_FLY_ANIM

Requires CMaNGOS 12799+
[3073] Use the encounter frames in Ruby Sanctum and Icecrown Citadel

Note:
Encounter frames need to be implemented for Gunship battle when available
Moreover ENCOUNTER_FRAME_UNK7 need to be send for Halion on player realm shift (real to twilight and reverse)

Expects Cmangos 12668+