Frontend - Select files with checkbox to enable tool selection

[JonasBerx]

• [x] Select files
• [x] Only allow 1 of each filetype to be selected.

[JonasBerx]

• [x] Snackbox message if more than 1 of same type is selected

[JonasBerx]

• [x] Depending on files selected, enable or disable menu options to SIMOD, PROSIMOS or OPTIMOS