Add NoteService to handle note operations

NoteService should be the only class with access to NoteDao;
nowhere else should NoteDao be accessed directly.

Channel dependencies are static in PacketProcessor, for now.
Ideally they would be injected in the constructor,
but since the constructor is private and I don't want to open
up that can of worms, I'll leave it like this.
At the very least, now we have a way of injecting services into
the handlers. This will make further restructuring way easier.

src/main/java/client/processor/npc/FredrickProcessor.java

@@ -31,7 +31,7 @@ import client.inventory.Item;
 import client.inventory.ItemFactory;
 import client.inventory.manipulator.InventoryManipulator;
 import database.DaoException;
-import database.NoteDao;
+import database.note.NoteDao;
 import model.Note;
 import net.server.Server;
 import net.server.world.World;