The searching, sitting, and digging states of sniffers aren't saved to NBT

The Bug:

The searching, sitting, and digging states of sniffers aren't saved to NBT.

As a result of this issue, the searching, sitting, and diggings states of a sniffer resets when its NBT data is reloaded. For example, upon the sniffer changing dimensions or the world being reloaded, its searching, sitting, and digging states aren't saved.

Steps to Reproduce:

1. Summon a sniffer and wait for it to begin searching, sitting, or digging.
2. As it does this, quickly leave and rejoin the world.
3. Observe if the sniffer is still searching, sitting, or digging.
4. Take note as to whether or not the searching, sitting, and digging states of sniffers are saved to NBT.

Observed Behavior:

The said states of sniffers aren't saved to NBT.

Expected Behavior:

The said states of sniffers would be saved to NBT.