"EnrichmentMap - show in pathway commons Functionality" - no expression data needs an error message

[risserlin]

When you click on "EnrichmentMap - show in pathway commons Functionality" and you don't have expression data (you only have a ranked list for example) then pathway commons just keeps spinning with no results. --> add warning or error message that you can't perform search.

Regular pathway commons works without expression data so in this case it would be good to warn the user but still show the pathway anyways just without the overlap.

But also, why can't it work with ranks instead of the expression data.