Re #8911. QtProperties can have options that can be displayed.
Re #8911. Added a custom interface for multi-fitting.
Re #8811. Plotting of spectra
Re #8911. Adding Global option to FunctionBrowser.
Re #8911. Added editor for property options.
Re #8911. Create the multidomain function.
Re #8911. Fitting and plotting results.
Re #8911. Button editor for local parameters.
Re #8911. Edit local parameters.
Re #8911. Setting local parameter values and ties.
Merge branch 'feature/8911_multi_data_fititng' into develop