Enter Time of Flight user properties in Spectrum Viewer

[MikeSullivan7]

Issue

Closes #2158

Description

A section has been added to the left hand side of the spectrum viewer which allows users to enter the Flight Path (meters) and the Time Delay (microseconds) used as these can change from experiment to experiment. The time delay can be used to artificially alter the neutron wavelength range. It was requested by IMAT that these option be "on show" rather than hidden away in a right click menu for example.

When the values in the spinboxes are changed, the associated attribute is altered in the unit_conversion object in the spectrum viewer model. This ensures that the converted data is recalculated properly when the ToF properties are changed and any alterations are contained in the UnitConversion class.

Testing

make check

Acceptance Criteria

• Open MI and load data with no spectrum.txt data
• In the SV, the Right Click Units option should be disabled and the ToF properties options on the left should be greyed out
• Load in data with a spectrum.txt file, e.g. the Brass dataset.
• The ToF properties box will be enabled and you can alter the Flight Path (FP) and Time Delay (TD).
• The defaults should be FP = 56m and TD = 0.
• For the Image Index mode, the FP and TD should not alter the data.
• For the Wavelength mode, the increasing the FP implies faster neutrons (with a fixed time of flight) so the wavelength should shift to a smaller number.
• For the Energy mode, the increasing the FP implies faster neutrons (with a fixed time of flight) so the wavelength should shift to a higher number.
• For the ToF us mode, changing the FP should not change the data but the TD will shift the data to the left or right by the value of the TD.
• For the Corrected Brass Dataset (\\isis\shares\IMAT\ExampleData\Brass\Corrected_Sample_PH20), there should be a Bragg Edge around 4.3 angstroms.

Documentation

Will add Release Note

[coveralls]

coverage: 73.812% (-0.5%) from 74.286%
when pulling 5210976 on 2158_Tof_user_properties
into b6087e8 on main.