IocTestFramework: Generalise to work for CLF

As a developer in CLF I would like to make use of the IOCTestFramework to test my IOCs. Some changes that need to be made to use it:
* CLF use Linux, the IOCTestFramework needs to work for both Linux/Windows
* The IOCTestFramework currently uses genie_python for channel access, solutions to this are:
1. Make it optionally load genie_python or some other channel access library
1. Remove genie_python entirely and just use a different channel access library
1. Make genie_python public
* Make it configurable where to start IOCs from

@chris-d-gregory is happy to do this work