Core/Spell: define channels without movement interrupt flags as allowed move

- Remove script hacks no longer needed

(cherry picked from commit 3a0cb90ea994e82dd8c70888fb847082f738d5dc)

src/server/game/Spells/SpellInfo.cpp

@@ -1675,7 +1675,7 @@ bool SpellInfo::IsChanneled() const
 
 bool SpellInfo::IsMoveAllowedChannel() const
 {
-    return IsChanneled() && HasAttribute(SPELL_ATTR5_CAN_CHANNEL_WHEN_MOVING);
+    return IsChanneled() && (HasAttribute(SPELL_ATTR5_CAN_CHANNEL_WHEN_MOVING) || (!(ChannelInterruptFlags[0] & (AURA_INTERRUPT_FLAG_MOVE | AURA_INTERRUPT_FLAG_TURNING))));
 }
 
 bool SpellInfo::NeedsComboPoints() const

src/server/scripts/Northrend/IcecrownCitadel/boss_blood_prince_council.cpp

@@ -1129,10 +1129,7 @@ class npc_dark_nucleus : public CreatureScript
                     if (Unit* victim = me->GetVictim())
                     {
                         if (me->GetDistance(victim) < 15.0f && !victim->HasAura(SPELL_SHADOW_RESONANCE_RESIST, me->GetGUID()))
-                        {
                             DoCast(victim, SPELL_SHADOW_RESONANCE_RESIST);
-                            me->ClearUnitState(UNIT_STATE_CASTING);
-                        }
                         else
                             MoveInLineOfSight(me->GetVictim());
                     }
@@ -1146,7 +1143,6 @@ class npc_dark_nucleus : public CreatureScript
                 }
 
                 DoCast(who, SPELL_SHADOW_RESONANCE_RESIST);
-                me->ClearUnitState(UNIT_STATE_CASTING);
             }
 
             void DamageTaken(Unit* attacker, uint32& /*damage*/) override

src/server/scripts/Northrend/IcecrownCitadel/boss_professor_putricide.cpp

@@ -933,7 +933,6 @@ class spell_putricide_ooze_channel : public SpellScriptLoader
 
             void StartAttack()
             {
-                GetCaster()->ClearUnitState(UNIT_STATE_CASTING);
                 GetCaster()->DeleteThreatList();
                 GetCaster()->ToCreature()->AI()->AttackStart(GetHitUnit());
                 GetCaster()->AddThreat(GetHitUnit(), 500000000.0f);    // value seen in sniff

src/server/scripts/Northrend/IcecrownCitadel/boss_the_lich_king.cpp

@@ -725,7 +725,6 @@ class boss_the_lich_king : public CreatureScript
                             summon->CastSpell(summon, SPELL_ICE_SPHERE, false);
                             summon->CastSpell(summon, SPELL_ICE_BURST_TARGET_SEARCH, false);
                             summon->CastSpell(target, SPELL_ICE_PULSE, false);
-                            summon->ClearUnitState(UNIT_STATE_CASTING);
                             summon->GetMotionMaster()->MoveFollow(target, 0.0f, 0.0f);
                         }
                         else

src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_loken.cpp

@@ -161,7 +161,6 @@ public:
                         break;
                     case EVENT_RESUME_PULSING_SHOCKWAVE:
                         DoCast(me, SPELL_PULSING_SHOCKWAVE_AURA, true);
-                        me->ClearUnitState(UNIT_STATE_CASTING); // This flag breaks movement.
                         DoCast(me, SPELL_PULSING_SHOCKWAVE, true);
                         break;
                     case EVENT_INTRO_DIALOGUE:

src/server/scripts/Northrend/Ulduar/Ulduar/boss_kologarn.cpp

@@ -230,8 +230,6 @@ class boss_kologarn : public CreatureScript
                 summon->CastSpell(summon, SPELL_FOCUSED_EYEBEAM_PERIODIC, true);
                 summon->CastSpell(summon, SPELL_FOCUSED_EYEBEAM_VISUAL, true);
                 summon->SetReactState(REACT_PASSIVE);
-                // One of the above spells is a channeled spell, we need to clear this unit state for MoveChase to work
-                summon->ClearUnitState(UNIT_STATE_CASTING);
 
                 // Victim gets 67351
                 if (!eyebeamTarget.IsEmpty())

src/server/scripts/Northrend/Ulduar/Ulduar/boss_mimiron.cpp

@@ -1304,7 +1304,6 @@ class npc_mimiron_assault_bot : public CreatureScript
                     {
                         case EVENT_MAGNETIC_FIELD:
                             DoCastVictim(SPELL_MAGNETIC_FIELD);
-                            me->ClearUnitState(UNIT_STATE_CASTING);
                             events.RescheduleEvent(EVENT_MAGNETIC_FIELD, 30000);
                             break;
                         default:

src/server/scripts/Outland/BlackTemple/boss_illidan.cpp

@@ -2305,7 +2305,6 @@ class spell_illidan_find_target : public SpellScriptLoader
                 if (Creature* caster = GetCaster()->ToCreature())
                 {
                     caster->CastSpell(target, SPELL_PARALYZE, true);
-                    caster->ClearUnitState(UNIT_STATE_CASTING);
                     caster->AI()->SetGUID(target->GetGUID(), 0);
                 }
             }