Add checkboxes to raw file list

[JuliaS92]

Is your feature request related to a problem? Please describe. I often want to run different analysis runs on different selections of files, or simply exclude reinjections from the analysis. Currently all raw files in a folder are analysed, which would mean moving raw files around a lot to adjust the analysis.

Describe the solution you'd like You could add a checkbox for every raw file to unselect the ones you want to exclude for the current run.

Additional context This includes hdf files from previous analyses, which should however be fixed by #241 as long as you don't look for files recursively (didn't check whether that is the case)

[straussmaximilian]

Files can now be excluded with the new file input widget.