Refactor pet action management: rename PetAction to PetBasicAction, update related properties and methods, and enhance pet stats with maximum values.

Models/PetUpdateActionRequest.cs

@@ -2,7 +2,7 @@ namespace pet_companion_api.Models
 {
     public class PetUpdateActionRequest
     {
-        public PetAction? Action { get; set; }
-        public PetActionGather? PetActionGather { get; set; }
+        public PetBasicAction? BasicAction { get; set; }
+        public PetActionGather? GatherAction { get; set; }
     }
 }