Improve non-XYZ beams and panels DX

[ahdinosaur]

i could imagine 3 ways you'd want to express this, for different use cases:

1. start at this grid position, end at this grid position
2. start at this grid position, go in this direction for this length.
3. rotate this group by an arbitrary rotation (Euler angle).

the real challenge will be chaining non-xyz beams. like the open shelves have many hinges in series. the grid position of the beams stops making sense. so for that i'd think of nested groups.

[ahdinosaur]

Improve non-XYZ beams and panels DX