This reverts commit ab984a0711.
The block damage is null *and has been* null in cases where the block
has already been cleared. Consumers are supposed to use the
getDamagerBlockState instead.
Always passes the respective block to a damage source when passing a
block state. While we could technically use the damageSourcePosition
here by, we'd have to translate it back to a block position by
subtracting .5 from all its components.
Such behaviour however relies on the caller logic's mutation of the
damageSourcePosition and will break once this position is not the centre
of the block.
Passing in the block at the specific callsite is a lot more future
proof.
