[Feature] Implemented /shield ability and related affects (#1494)

* shield ability initial work

* updates

* update

* updates

* Update client_process.cpp

* major updates

optimized
pet support
perl support

* updates

* minor update

* fix merge error

* requested changes

* variable fix

* optimization

* minor update

* Revert "optimization"

This reverts commit 27e11e758b.

* fix

reset variables on shield_target if shielder dies or zones during shielding.

* edge case fix

Catch and fix situations where shield target doesn't have shielder variable cleared. Can occur if shielder . uses ability when target is not in combat then zones.

* combined packet and mob function

Shield now uses a common pathway through ShieldAbility, added parameters to perl function

* Addressing formatting for Kayen

* Fix function typo

Co-authored-by: Akkadius <akkadius1@gmail.com>

zone/spell_effects.cpp

@@ -2950,6 +2950,19 @@ bool Mob::SpellEffect(Mob* caster, uint16 spell_id, float partial, int level_ove
 				break;
 			}
 
+			case SE_PetShield: {
+				if (IsPet()) {
+					Mob* petowner = GetOwner();
+					if (petowner) {
+						int shield_duration          = spells[spell_id].base[i] * 12 * 1000;
+						int shield_target_mitigation = spells[spell_id].base2[i] ? spells[spell_id].base2[i] : 50;
+						int shielder_mitigation      = spells[spell_id].max[i] ? spells[spell_id].base2[i] : 50;
+						ShieldAbility(petowner->GetID(), 25, shield_duration, shield_target_mitigation, shielder_mitigation);
+						break;
+					}
+				}
+			}
+
 			case SE_Weapon_Stance: {
 				if (IsClient()) {
 					CastToClient()->ApplyWeaponsStance();
@@ -3170,7 +3183,6 @@ bool Mob::SpellEffect(Mob* caster, uint16 spell_id, float partial, int level_ove
 			case SE_LimitManaMax:
 			case SE_DoubleRangedAttack:
 			case SE_ShieldEquipDmgMod:
-			case SE_GroupShielding:
 			case SE_TriggerOnReqTarget:
 			case SE_LimitRace:
 			case SE_FcLimitUse: