Making file preview human-readable

Non-text based file formats are not human-readable in the GUI preview. I suggest amending this by adding a conversion/decoding step.

Examples include:

• UML format: requires preprocessing using ASE functions
  • GPAW (.gpw file)
  • ASAP (.traj file)
• CDF format: somewhat human-readable, but the layout is too horizontal + some symbols are not properly rendered.
  • ATK (.atk file)
  • GROMACS (.edr file)
• Several NAMD files are encrypted

I'm excluding xml files, since these are quite human-readable.