[MTR4] CP 3400 Series

Fixed a bug where the floor was incorrecticly rendering as an EXTERIOR part. Additionally, cleaned up the pack's files to remove unnecessary definition/properties jsons.

Added Realistic Pantographs:

• These pantographs (compatible with both 5 and 6 block overhead wires) will automaticly rise when a train enters service (either through ATO or by having a driver on the train that's holding a key) and will automatically lower when the train exits service.
• This new feature is compatible with the old pantographs - you do not have to change any depots/sidings if you were already using this pack. Once you update, your CP 3400 trains should feature the new pantographs!

If you retextured this train, you should redownload the pack, and copy the cp3400_base.png file to the updated pack.