Basic structure for ConvertToYSpace algorithm

Refs #8598
Refactoring to avoid code duplication.

* getComponentParameter is now only defined in ConvertToYSpace
* DetectorParams struct has moved to ConvertToYSpace
* Y calculation has moved to ConvertToYSpace

Refs #8598
Tidy up in ConvertToYSpace and implement exec test

Refs #8598
Set units on output workspace.

Refs #8598
Implement a profile function to fit a mass peak in Y-space.

Used in neutron compton scattering to Fit a spectrum using only the proton
peak.
Refs #8598
Start of NormaliseByPeakArea algorithm

Refs #8598
Refactor test helper to allow multiple spectra.

Refs #8598
Symmetrised output is correct for non-sum behaviour

Refs #8598
Implement summing behaviour in NormaliseByPeakArea.

Refs #8598
Fix default value of test helper create2DWorkspaceWithFullInstrument

Accidentally changed the behaviour that everyone else was expecting.
Refs #8598
Fix silly unit test mistake.

Refs #8598
Fix system VesuvioFitting tests.

Converting the TOF from seconds to microseconds and then back seems
to have caused instability in the fitting when including the background.
It is actually more sensible to have convertToYSpace take the time in
seconds anyway.
Refs #8598
Fix cppcheck scope error.

Refs #8598
Fix doxygen warning.

Refs #8598
Put back accidentally removed variable.

Refs #8598
Merge remote-tracking branch 'origin/feature/8598_convert_to_yspace'