Make shared library thread-safe

[jimkring]

At present, there is a very good likelihood that the shared library is not thread safe. As such, all of the call library function (CLF) nodes are configured to run in the user interface thread of LabVIEW. This means that the DLL is thus always called from the same thread (which addresses thread safety issues), but, it can also create undesirable behaviors in relationship to the user interface and the “root loop”.

It could be possible that using a different data structure than Box<> for object references would be sufficient.

More research and investigation needs to be done around thread safety and our approach to calling rust code from LabVIEW.

[JamesMc86]

I've seen references that you need a Box for this case which would make sense. You still have to handle the case of wire branches though so would probably need to make sure this is a reference type in LabVIEW with a cleanup "close" method.