[Quest API] Add TaskSelector to Perl/Lua. (#2177)

- Add $client->TaskSelector(task_list) to Perl.
- Add client:TaskSelector({task_list}) to Lua.
- Allow $client->AssignTask(task_id) in Perl.
- Allow client:AssignTask(task_id) in Lua.
- Can now assign tasks in scripts without the NPC ID parameter.

zone/client.h

@@ -1236,7 +1236,7 @@ public:
 	}
 	inline void AssignTask(
 		int task_id,
-		int npc_id,
+		int npc_id = 0,
 		bool enforce_level_requirement = false
 	) {
 		if (task_state) {