Resolve "gene variants in molart"

Closes #500 (closed)

Hi @david.hoksza,

This merge request will give you access to amino acid change for gene variant. To get information about gene variant for molart integration you would have to do something similar to:

      map.getTopMap().getVisibleDataOverlays().then(function(dataOverlays){
        var overlay = dataOverlays[0];
        return overlay.getFullAliasById(elementId);
      }).then(function(aliasOverlayData){
        // here you have access to all gene variants for element elementId that are available in 
        // the first visible data overlay (there is aminoAcidChange property defined for a single variant)
        aliasOverlayData.getGeneVariants()
      });

In the attachment you can find example file that can be uploaded into the system: gene_variants_aa_change.txt