Core/Spells: Merge TRIGGERED_IGNORE_AURA_INTERRUPT_FLAGS functionality into TRIGGERED_IGNORE_CAST_IN_PROGRESS as they are always used together (and missing one of them in scripts is a common enough mistake)

* Also fixes Ray of Frost being interrupted by casting Shimmer

src/server/game/Spells/Spell.cpp

@@ -3538,7 +3538,7 @@ SpellCastResult Spell::prepare(SpellCastTargets const& targets, AuraEffect const
         {
             // stealth must be removed at cast starting (at show channel bar)
             // skip triggered spell (item equip spell casting and other not explicit character casts/item uses)
-            if (!(_triggeredCastFlags & TRIGGERED_IGNORE_AURA_INTERRUPT_FLAGS) && !m_spellInfo->HasAttribute(SPELL_ATTR2_NOT_AN_ACTION))
+            if (!(_triggeredCastFlags & TRIGGERED_IGNORE_CAST_IN_PROGRESS) && !m_spellInfo->HasAttribute(SPELL_ATTR2_NOT_AN_ACTION))
                 unitCaster->RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::Action, m_spellInfo);
 
             // Do not register as current spell when requested to ignore cast in progress
@@ -3917,7 +3917,7 @@ void Spell::_cast(bool skipCheck)
     if (!(hitMask & PROC_HIT_CRITICAL))
         hitMask |= PROC_HIT_NORMAL;
 
-    if (!(_triggeredCastFlags & TRIGGERED_IGNORE_AURA_INTERRUPT_FLAGS) && !m_spellInfo->HasAttribute(SPELL_ATTR2_NOT_AN_ACTION))
+    if (!(_triggeredCastFlags & TRIGGERED_IGNORE_CAST_IN_PROGRESS) && !m_spellInfo->HasAttribute(SPELL_ATTR2_NOT_AN_ACTION))
         m_originalCaster->RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::ActionDelayed, m_spellInfo);
 
     if (!m_spellInfo->HasAttribute(SPELL_ATTR3_SUPPRESS_CASTER_PROCS))

src/server/game/Spells/SpellDefines.h

@@ -249,10 +249,10 @@ enum TriggerCastFlags : uint32
     TRIGGERED_IGNORE_CAST_IN_PROGRESS               = 0x00000020,   //!< Will not check if a current cast is in progress
     // reuse                                        = 0x00000040,
     TRIGGERED_CAST_DIRECTLY                         = 0x00000080,   //!< In Spell::prepare, will be cast directly without setting containers for executed spell
-    TRIGGERED_IGNORE_AURA_INTERRUPT_FLAGS           = 0x00000100,   //!< Will ignore interruptible aura's at cast
+    // reuse                                        = 0x00000100,
     TRIGGERED_IGNORE_SET_FACING                     = 0x00000200,   //!< Will not adjust facing to target (if any)
     TRIGGERED_IGNORE_SHAPESHIFT                     = 0x00000400,   //!< Will ignore shapeshift checks
-    // reuse
+    // reuse                                        = 0x00000800,
     TRIGGERED_DISALLOW_PROC_EVENTS                  = 0x00001000,   //!< Disallows proc events from triggered spell (default)
     TRIGGERED_IGNORE_CASTER_MOUNTED_OR_ON_VEHICLE   = 0x00002000,   //!< Will ignore mounted/on vehicle restrictions
     // reuse                                        = 0x00004000,