Some problems with saving/placing prebuilt rides

[YoloSweggLord]

While I was trying to make some prebuilt rides, I noticed some problems:

• If the ride being placed has an invalid ride mode, the ride will not be built (though any scenery saved with the ride will be), but the ride will still exist as a phantom-similar to destroying a roller coaster, piece by piece, without the permissions to demolish rides.
• Any scenery saved with the ride but with overlapping clearance (i.e. scenery placed with zc to be closer to the track or in the ride booths) will not be placed when a prebuilt ride is placed, even if zero clearance is on. It is either not being saved or not being built.
• Also, a suggestion, when saving scenery with a ride, we should be able to select a rectangle of land by clicking and dragging from one corner to another, and any scenery and path in that square will be selected.