Fix bug when objects start in a positive halo

Objects with a thickness (triangles and circular sectors) can no longer
extend beyond the grid in the dimension they are aligned to.

Building these objects where the lower extent is aligned with a positive
halo, no longer corrupts memory due to out of bounds memory access

reframe_tests/tests/src/geometry_tests/cylindrical_sector_geometry/cylindrical_sector_z_outside_boundary.in

@@ -8,6 +8,6 @@
 #rx: 0.080 0.080 0.080
 
 #material: 8 0 1 0 half_space
-#cylindrical_sector: z 0.07 0.06 0.04 0.12 0.05 30 240 half_space
+#cylindrical_sector: z 0.07 0.06 0.04 0.1 0.05 30 240 half_space
 
 #geometry_objects_write: 0 0 0 0.1 0.1 0.1 full_volume