Add automatic lift floor hole generation

[luca-della-vedova]

New feature implementation

Implemented feature

This PR adds automatic lift floor hole generation for lift shafts. It switches our path library from lyon to geo since the latter supports boolean operations between polygons, otherwise we would have to write our own.

Example below:

Screencast.from.2024-01-12.11-02-03.webm

[mxgrey]

Automatically cutting the lift holes is an excellent capability. I've left some in-line comments about spots where the implementation can be improved, but there's one thing I noticed in particular that I'm not sure where in the code it would be happening:

When a floor is completely divided on two sides by a lift, one entire half of the floor will end up being deleted. To illustrate this, here are some before and after screenshots of the hotel. In the "after" picture, I've moved the lift into the hallway in such a way that the hallway should be fully split in two. Instead, only half of the hallway remains at all:

Before

After

[luca-della-vedova]

When a floor is completely divided on two sides by a lift, one entire half of the floor will end up being deleted.

Yea I noticed this as well and I think it's just a consequence of the triangulation algorithm.
I tried all the difference triangulation algorithms in the library and I believe I found the one that gives the best outcome here. The outline is still a bit messed up but the polygon shape itself seems to be OK in all the cases I could test (including the hall example you brought up).

[mxgrey]

I noticed that the gap calculation was still missing the lift wall thickness, causing the gaps to be too small:

I've pushed a commit that just adds the wall thickness parameter, so now the gaps are coming out as intended:

Looks good now! We can merge this as soon as CI passes.