Feature read nicos and crash fix
This MR covers importing 2D Nicos files (*.001). Besides this, the file-open-dialog filters have been divided into parts: TIFF, Nicos, BornAgain, CSV, all
The "CSV" entry is no new reader, but just to provide a filter for relevant files. It still directs to the default ASCII reader, same as before.
The above is tracked in #4 (closed)
Also part of the MR is the fix for issue #2 (closed).
Edited by m.puchner