[Cleanup] "equipped" not "equiped", "dual" not "duel". (#3149)

* [Cleanup] "equipped" not "equiped", "dual" not "duel".

# Notes
- These are spelled incorrectly.

* Update spdat.h

* Formatting further.

* Update api_service.cpp

zone/spell_effects.cpp

@@ -8075,8 +8075,8 @@ bool Mob::PassCastRestriction(int value)
 				return true;
 			break;
 
-		case IS_OFF_HAND_EQUIPED:
-			if (HasShieldEquiped() || CanThisClassDualWield())
+		case IS_OFF_HAND_EQUIPPED:
+			if (HasShieldEquipped() || CanThisClassDualWield())
 				return true;
 			break;
 
@@ -9284,7 +9284,7 @@ void Mob::SendCastRestrictionMessage(int requirement_id, bool target_requirement
 	case IS_HP_UNDER_50_PCT:
 		Message(Chat::Red, fmt::format("{}  This target must be at oe below 50 pct of its maximum hit points.", msg).c_str());
 		break;
-	case IS_OFF_HAND_EQUIPED:
+	case IS_OFF_HAND_EQUIPPED:
 		Message(Chat::Red, fmt::format("{} You must be wielding a weapon or shield in your offhand to use this ability.", msg).c_str());
 		break;
 	case HAS_NO_PACT_OF_FATE_RECOURSE_BUFF: