Feature/refine processing

related #52

Processing for slf to med conversion

• add slf2med processing to be able to use salome_script.py refine

Implemented options of salome_script.py refine

-l refine level

--domain refine domain

--method refine method

Graphical user interface

• processing refine user interface

Documentation

• first version of documentation (slf2med and refine)

Tests

• creation of QGIS tests based on test_refine.sh

Limitation

⚠ For tests we are only checking if processing has no errors. We can't do binary comparison of results.