[GUI] Rightclick to open outputfile

Problem to solve

If one works with output processors it is useful to quickly open the output file generated by any processor by using a standard text editor to check what the output looks like.

Further details

To make it more easy it would be helpful if one can right click on an output file in the GUI and select open with or just open. This speeds up the working progress and the user does not have to go to project folder by himself.