QMM should be able to display j-value interval

[RadixSeven]

When looking for peaks, the j-value of a multiplet can distinguish between several candidate peaks. So, the interface should allow the display of lines a given number of Hz away from the candidate peak.

A quick way would be to just display one j-value distance from the currently selected peak. There would be a checkbox that said "display j-line" with a type-able drop-down menu next to it from which you can select one of the given j-values or enter your own.

This will require storing the acquisition Hz for the spectra. I think the interface should leave that unknown until needed (when the display j-lines is checked) and then request it from the user. The acquisition Hz should be stored in the collection object - that way, it will propagate to the residuals and bins etc, as well as to the spectrum copy mailed to me. I think that the field for this should be called frequency_of_1h (1h_frequency would be shorter but Matlab identifiers cannot start with digits). That way it will also be immediately available if we add it to the metadata coming from BIRG. This is a per-spectrum property.

I can give a default value in the dialog for the acquisition Hz using the one for Reo's lab's spectrometer. This will make it easy for our most common users.

The dialog can also have a check-box (checked by default) for "use this frequency for all spectra"