Refs #8739 Update ConvFit to match new parameters.
Refs #8739 Update reference results.

The fit is still the same, but the x-values have changed because we're now using ConvertSpectrumAxis.
Refs #8739 Update system tests to match.
Refs #8739 Update test workspace names to reflect changes.
Refs #8739 Correct output workspace names.
Merge branch 'feature/8739_temp_param_in_convfit' into develop