Refactor the 3D mesh and occupancy grid generation

[argenos]

This should be moved to the scenery_builder.

[argenos]

Based on the contents of the composable model representation, this requires #10 to be solved first

[argenos]

These modifications should also be moved to the scenery builder (if they are still necessary):

FloorPlan-DSL/src/exsce_floorplan/floor_plan/classes/wall_opening.py

Lines 54 to 73 in c2d5db4

	# Modifications to the vertices made to avoid face clashing
	threshold = 0.01
	modifications = np.where(origin[2] == vertices[:, 2], -threshold, 0)
	modifications += np.where(self.wall_a.height == vertices[:, 2], threshold, 0)
	if not self.wall_b is None:
	modifications += np.where(
	self.wall_b.height == vertices[:, 2], threshold, 0
	)
	modifications = np.hstack(
	(
	np.zeros((len(modifications), 2)),
	modifications.reshape((len(modifications), 1)),
	)
	)
	vertices = vertices + modifications
	vertices[:, 1] -= threshold
	new_vertices = np.copy(vertices)
	new_vertices[:, 1] += self.thickness + threshold * 2