[MC-265727] Falling Blocks drop as items when falling on edge of blocks

Unlike falling on north-west, east-south edges cause falling blocks drop corresponded items instead of placing above blocks.

Place a stone on ground (surrounded with air :

/fill -1 -1 -1 1 -1 1 stone
/fill -1 0 -1 1 0 1 air
/setblock 0 0 0 stone

Summon a falling sand above it with x or z offest 0.5:
```
/summon falling_block 1.0 2.0 1.0
```

The falling sand turned to block above that stone.

The falling sand dropped its item.

Note that this doesn't happen if x and z both offest -0.5:

/summon falling_block 0.0 2.0 0.0

but still if quite exceed:

/summon falling_block -0.1 2.0 -0.1