Core/Misc: Refactor scripts to fix static analysis warnings

First batch of fixes targeting 100 issues reported by Coverity

src/server/scripts/World/guards.cpp

@@ -54,14 +54,22 @@ public:
 
     struct guard_genericAI : public GuardAI
     {
-        guard_genericAI(Creature* creature) : GuardAI(creature) { }
+        guard_genericAI(Creature* creature) : GuardAI(creature)
+        {
+            Initialize();
+        }
 
-        void Reset() override
+        void Initialize()
         {
             globalCooldown = 0;
             buffTimer = 0;
         }
 
+        void Reset() override
+        {
+            Initialize();
+        }
+
         void EnterCombat(Unit* who) override
         {
             if (me->GetEntry() == NPC_CENARION_HOLD_INFANTRY)
@@ -263,9 +271,12 @@ public:
 
     struct guard_shattrath_scryerAI : public GuardAI
     {
-        guard_shattrath_scryerAI(Creature* creature) : GuardAI(creature) { }
+        guard_shattrath_scryerAI(Creature* creature) : GuardAI(creature)
+        {
+            Initialize();
+        }
 
-        void Reset() override
+        void Initialize()
         {
             banishTimer = 5000;
             exileTimer = 8500;
@@ -273,6 +284,11 @@ public:
             canTeleport = false;
         }
 
+        void Reset() override
+        {
+            Initialize();
+        }
+
         void UpdateAI(uint32 diff) override
         {
             if (!UpdateVictim())
@@ -328,9 +344,12 @@ public:
 
     struct guard_shattrath_aldorAI : public GuardAI
     {
-        guard_shattrath_aldorAI(Creature* creature) : GuardAI(creature) { }
+        guard_shattrath_aldorAI(Creature* creature) : GuardAI(creature)
+        {
+            Initialize();
+        }
 
-        void Reset() override
+        void Initialize()
         {
             banishTimer = 5000;
             exileTimer = 8500;
@@ -338,6 +357,11 @@ public:
             canTeleport = false;
         }
 
+        void Reset() override
+        {
+            Initialize();
+        }
+
         void UpdateAI(uint32 diff) override
         {
             if (!UpdateVictim())