Oncoprint config user session

[BasLee]

Duplicate of https://github.com/cBioPortal/cbioportal-frontend/pull/4230 to circumvent circleci build problems when building from organisation repo.

[alisman]

@bas, the button shouldn't show in logged-out state. You can test this by running the branch against production site. Or even just hitting localhost:3000 directly. This is an easy fix, just look at appStore to find out if user is logged out.