MK3 Chopper IOC & OPI: disable direction controls according to property on server

A recent discovery as to how all the various discs are configured lead to some changes in the VI, and these now need to be replicated in the IOC and OPI.

It is already known that T0 choppers can't change direction and it has now come to light that some disc choppers can't either. Fortunately there is a server property that can be read, namely `GetStoredDirectionChangeEnabled`, which is a Boolean value. The appropriate action can then be taken e.g. disable direction change control.

It may be more efficient to just read the state of this property to determine whether or not a chopper can change direction rather than first checking what type it is and then the property. i.e. both T0 and disc choppers will have this property set.