[Muon] Sequential fitting

[Anders-Markvardsen]

Chat with Adroja this morning.

Take MUSR run 43001 - etc

Would like to improve the automation of sequential fit of such data.

There is a least two options for this

1A) Allow hundreds of files to be specified in the Home tab, where
each of these are processed independently. This will generate hundreds of Workspaces, one for each run, and one or many plots depending on how the settings is in the Settings tab

1B) Select the Data Analysis tab. Enable a version of 'sequential fit' which allow user to select any number of workspaces generated in 1B for sequentially fittting

Another implementation option is

2A) In data analysis tab through a 'sequential fit' implementation directly allow user to select files, which are then processed according to GUI setttings before fitting.

First task is to agree on the user experience of this

[Anders-Markvardsen]

This issue was originally trac ticket 6473