Add tests for, and fix, the conversion of Python values to Discreet functions
Add tests for, and fix, the conversion of Python values to Discreet functions (cern.japc.value.spi.value.simple.DiscreteFunctionValue)
I don't have confidence in the checkDims part of this though, so further work possibly needed to add coverage for that part.
cc @rgorbono for the suggested fix. cc @mhrabia for the original motivation.