fix(Core/Spells): several improvements to cooldowns (#7559)

- Reworked spell category cooldowns.
- Implemented category cooldowns for pets.
- Properly shows pet spell cooldowns in player's UI.
- Corrected pet spell cooldowns with infinity duration.
- Do not add/remove infinity spell cooldown on aura apply/remove if casted by item.
- Closes #5263

src/server/game/DataStores/DBCStores.cpp

@@ -395,7 +395,7 @@ void LoadDBCStores(const std::string& dataPath)
 
     for (auto i : sSpellStore)
         if (i->Category)
-            sSpellsByCategoryStore[i->Category].insert(i->Id);
+            sSpellsByCategoryStore[i->Category].emplace(false, i->Id);
 
     for (SkillRaceClassInfoEntry const* entry : sSkillRaceClassInfoStore)
     {