Core/Spells: rework part 4: iterate over effects first

Port From (https://github.com/TrinityCore/TrinityCore/commit/65dca120d34febdaa84a63e17f638ab0fa59b3df)

Source/Game/Spells/SpellEffects.cs

@@ -909,7 +909,7 @@ namespace Game.Spells
                 if (unitTarget.HasAura(48920) && ((uint)(unitTarget.GetHealth() + (ulong)addhealth) >= unitTarget.GetMaxHealth()))
                     unitTarget.RemoveAura(48920);
 
-                m_damage -= addhealth;
+                m_healing -= addhealth;
             }
         }
 

Source/Game/Spells/SpellInfo.cs

@@ -2657,14 +2657,16 @@ namespace Game.Spells
         public int GetDuration()
         {
             if (DurationEntry == null)
-                return 0;
+                return IsPassive() ? -1 : 0;
+
             return (DurationEntry.Duration == -1) ? -1 : Math.Abs(DurationEntry.Duration);
         }
 
         public int GetMaxDuration()
         {
             if (DurationEntry == null)
-                return 0;
+                return IsPassive() ? -1 : 0;
+
             return (DurationEntry.MaxDuration == -1) ? -1 : Math.Abs(DurationEntry.MaxDuration);
         }
 
@@ -4021,18 +4023,6 @@ namespace Game.Spells
             return false;
         }
 
-        public bool IsFarUnitTargetEffect()
-        {
-            return (Effect == SpellEffectName.SummonPlayer)
-                || (Effect == SpellEffectName.SummonRafFriend)
-                || (Effect == SpellEffectName.Resurrect);
-        }
-
-        bool IsFarDestTargetEffect()
-        {
-            return Effect == SpellEffectName.TeleportUnits;
-        }
-
         public bool IsUnitOwnedAuraEffect()
         {
             return IsAreaAuraEffect() || Effect == SpellEffectName.ApplyAura || Effect == SpellEffectName.ApplyAuraOnPet;

Source/Game/Spells/SpellManager.cs

@@ -3304,14 +3304,6 @@ namespace Game.Entities
                     case 64234: // Gravity Bomb (25m) (XT-002)
                         spellInfo.MaxAffectedTargets = 1;
                         break;
-                    case 62834: // Boom (XT-002)
-                                // This hack is here because we suspect our implementation of spell effect execution on targets
-                                // is done in the wrong order. We suspect that 0 needs to be applied on all targets,
-                                // then 1, etc - instead of applying each effect on target1, then target2, etc.
-                                // The above situation causes the visual for this spell to be bugged, so we remove the instakill
-                                // effect and implement a script hack for that.
-                        spellInfo.GetEffect(1).Effect = 0;
-                        break;
                     case 64386: // Terrifying Screech (Auriaya)
                     case 64389: // Sentinel Blast (Auriaya)
                     case 64678: // Sentinel Blast (Auriaya)