[MC-219839] Powder Snow above dripstone doesn't fill cauldron below, unlike Water or Lava

Powder snow doesn't drip into a cauldron like water or lava does. (although understandably snow works differently than those fluids)

Place blocks in the air to form three holes
Place a lava, water and powder snow source block into the holes using their respective buckets
Place a pointed dripstone on the underside of the blocks at the bottom
Place a cauldron underneath each dripstone (see construction in screenshot)
Optionally run for instance this command:
```
/gamerule randomTickSpeed 10000
```
→ After waiting several minutes, notice the cauldron underneath the powder snow never gets filled, while the others do