Spawner rewrite

[Mads Boddum]

Spawner currently only works with static spawns and is coupled pretty tightly to StaticSpawnInfo. The problem is that StaticSpawnInfo is only creatable from a row in a SDB, which obviously won’t work well when we also need to create spawners at runtime.

Requirements

1. Spawner becomes an interface with all the methods that are currently exposed
2. StaticSpawner implements new interface Spawner and contains the logic that the old Spawner class held
3. com.projectswg.holocore.services.support.npc.spawn.SpawnerService#spawn should use StaticSpawner
4. Important that NPCCreator works with the Spawner interface and not StaticSpawner!

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