[8250] Cleanup code and data for spell_threat Author: nos4r2zod

* Load table data to std::map instead SQLStorage and add check loaded spell existance.
    * Drop from table not existed spells.

--HG--
branch : trunk

src/game/DBCStructure.h

@@ -1463,13 +1463,6 @@ struct SpellFocusObjectEntry
                                                             // 16 string flags, unused
 };
 
-// stored in SQL table
-struct SpellThreatEntry
-{
-    uint32      spellId;
-    int32       threat;
-};
-
 struct SpellRadiusEntry
 {
     uint32    ID;