Core/Spells: Implement CAST_FLAG_EX_IGNORE_COOLDOWN - causes spells to not automatically trigger cooldown clientside

Port From (https://github.com/TrinityCore/TrinityCore/commit/66509502f4a5065d74cb3da501558f7eff6ea1ec)

Source/Framework/Constants/Spells/SpellConst.cs

@@ -1557,7 +1557,7 @@ namespace Framework.Constants
         Unknown7 = 0x40,
         Unknown8 = 0x80,
         Unknown9 = 0x100,
-        Unknown10 = 0x200,
+        IgnoreCooldown = 0x200, // makes client not automatically start cooldown after SPELL_GO
         Unknown11 = 0x400,
         Unknown12 = 0x800,
         Unknown13 = 0x1000,

Source/Game/Spells/Spell.cs

@@ -43,6 +43,10 @@ namespace Game.Spells
             m_caster = (info.HasAttribute(SpellAttr6.CastByCharmer) && caster.GetCharmerOrOwner() != null ? caster.GetCharmerOrOwner() : caster);
             m_spellValue = new SpellValue(m_spellInfo, caster);
             m_castItemLevel = -1;
+
+            if (IsIgnoringCooldowns())
+                m_castFlagsEx |= SpellCastFlagsEx.IgnoreCooldown;
+
             m_castId = ObjectGuid.Create(HighGuid.Cast, SpellCastSource.Normal, m_caster.GetMapId(), m_spellInfo.Id, m_caster.GetMap().GenerateLowGuid(HighGuid.Cast));
             m_originalCastId = originalCastId;
             m_SpellVisual.SpellXSpellVisualID = caster.GetCastSpellXSpellVisualId(m_spellInfo);