Create a central monster registry in preparation for supporting quests and monster customization

[Syndaryl]

• As monsters are added to the dungeon, put them in the registry
• Assign monsters as individuals (the difference between 5 entries of 1 goblin, and one entry of 5 goblins - we should do 5 entries of 1 goblin)
• be able to flag monsters as quest targets, and provide a reference to said quest
• update rooms to be able to collect individuals into aggregates if they're all identical - display 5 identical goblins as one entry of 5 goblins.
• aggregation stage 2: if the only difference is name and they are all named, still cluster them but present a list of names.

[Syndaryl]

• Register a monsters 'home' - this is especially important for Wandering Monsters, but other monsters may not be in their 'home' room. If the same monster type appears elsewhere, have good odds of one of the populated rooms being 'home', size dependent?