Convert P1 piston connectors into models

[vrad-exe]

The non-reflective metal bits between P1 piston segments should be converted into models, to avoid vertex misalignment problems like this: The main piston cylinders still have to be brushes so we can use $envmaplightscale, but those don't tend to be affected by this.

[TeamSpen210]

It’s not quite as bad as it looks, because VBSP will automatically weld together vertices like this.

[vrad-exe]

It didn't seem to be doing that, this is in the P1 ceiling corridor. I've also had this same problem with trying to make these piston connectors in the past.