feat(Core/Util): AsUnderlyingType (#6117)

* Add AsUnderlyingType function to cast enum value to its underlying type (avoids repeating std::underlying_type everywhere)

(cherry picked from commit https://github.com/TrinityCore/TrinityCore/commit/fdd9227b232db9aae9bc4b2c60ca4de2cdaa0b54)
Co-Authored-By: Shauren <shauren.trinity@gmail.com>

src/common/Utilities/Util.h

@@ -892,4 +892,11 @@ private:
     EventStore _eventMap;
 };
 
+template<typename E>
+typename std::underlying_type<E>::type AsUnderlyingType(E enumValue)
+{
+    static_assert(std::is_enum<E>::value, "AsUnderlyingType can only be used with enums");
+    return static_cast<typename std::underlying_type<E>::type>(enumValue);
+}
+
 #endif