Dataset Types: Sticky, Normal, Volatile

Dataset types to improve deployment performance:

Sticky: is preinstalled on every hypervisor.

Normal: gets installed on first deploy and sticks around.

Volatile: gets installed on first deploy and automatically removed when the last vm using it is deleted.

Also it should be possible to remove datasets from the hypervisors once they get removed from fifo, so this needs some care since only datastes installed by fifo should be affected by this.