Add GUI elements to support logfiles.
The initial implementation should only display imported files, without the ability to edit them.
### DoD
- [x] Import existing logfile from the file system
- [x] Display the imported plot
- [ ] Export dialog to set the parameter of the new logfile
- [ ] Merge logfiles and save a new one
- [ ] Crop the merged logfile
First UI mockup; Top left are all the imported files; to the right infos about the selected logfile. The lower plot shows the merged logfile (See feature/logfileEditor)
Add GUI elements to support logfiles. The initial implementation should only display imported files, without the ability to edit them.