Rewrite trainer handling to properly support multiple trainers on the same creature

Framework/Constants/AccountConst.cs

@@ -578,7 +578,7 @@ namespace Framework.Constants
         CommandReloadMailLootTemplate = 669,
         CommandReloadMillingLootTemplate = 670,
         CommandReloadNpcSpellclickSpells = 671,
-        CommandReloadNpcTrainer = 672,
+        CommandReloadTrainer = 672,
         CommandReloadNpcVendor = 673,
         CommandReloadPageText = 674,
         CommandReloadPickpocketingLootTemplate = 675,

Framework/Constants/GossipConst.cs

@@ -36,7 +36,7 @@ namespace Framework.Constants
         Stablepet = 14,                   //Unit_Npc_Flag_Stable              (4194304)
         Armorer = 15,                   //Unit_Npc_Flag_Armorer             (4096)
         Unlearntalents = 16,                   //Unit_Npc_Flag_Trainer             (16) (Bonus Option For Trainer)
-        Unlearnpettalents = 17,                   //Unit_Npc_Flag_Trainer             (16) (Bonus Option For Trainer)
+        Unlearnpettalents_Old = 17,     // deprecated
         Learndualspec = 18,                   //Unit_Npc_Flag_Trainer             (16) (Bonus Option For Trainer)
         Outdoorpvp = 19,                   //Added By Code (Option For Outdoor Pvp Creatures)
         Max

Framework/Constants/SharedConst.cs

@@ -571,17 +571,22 @@ namespace Framework.Constants
 
     public enum TrainerType
     {
-        Class = 0,
-        Mounts = 1,
+        None = 0,
+        Talent = 1,
         Tradeskills = 2,
         Pets = 3
     }
     public enum TrainerSpellState
     {
-        Gray = 0,
-        Green = 1,
-        Red = 2,
-        GreenDisabled = 10
+        Known = 0,
+        Available = 1,
+        Unavailable = 2,
+    }
+
+    public enum TrainerFailReason
+    {
+        Unavailable = 0,
+        NotEnoughMoney = 1
     }
 
     public enum ChatMsg : uint