Better walls

Essentially making walls  have a bit more flexible options by tapping into a bit of the chiseled bookshelf tech/ stair placement tech.  In that having 3 lanes for placing of walls within a block; left, right and middle. Essentially the middle would behave as currently walls do however the left and right walls would essentially behave akin to vertical slabs.  This could be implemented for fences too.

In addition they could be placed to avoid the 'pillar' part by shift placing them as well, for more clean walls and the ability to place walls against other blocks without forcing the pillar part.