Implemented the T0.5 BRD Arena Challenge event (#1407)

* Fixed minimum range check searching for players WITHIN the range rather than a player OUTSIDE the range

* Implemented T0.5 BRD Ring of the Law Challenge event
Implemented AI for a number of the NPCs in the event, it should be rather difficult
Players can now wipe on the Ring of the Law event and continue either from the beginning, or at the boss if they are up to it
Added "Arena Spoils" game object spawn on successful completion of the T0.5 challenge

* Fixed scripts being blocked if no suitable targets were being found for spells - they just followed the target without attacking

* Fixed Malgen not chasing his target after feigning to lay a trap

src/scripts/ScriptLoader.cpp

@@ -49,6 +49,7 @@ void AddSC_spell_scripts();
 //eastern kingdoms
 void AddSC_instance_blackrock_spire();
 void AddSC_blackrock_depths();                       //blackrock_depths
+void AddSC_blackrock_depths_arena_challenge();
 void AddSC_boss_ambassador_flamelash();
 void AddSC_boss_anubshiah();
 void AddSC_boss_draganthaurissan();
@@ -314,6 +315,7 @@ void AddScripts()
 
     //eastern kingdoms
     AddSC_blackrock_depths();                               //blackrock_depths
+    AddSC_blackrock_depths_arena_challenge();
     AddSC_boss_ambassador_flamelash();
     AddSC_boss_anubshiah();
     AddSC_boss_draganthaurissan();