add more screenshots tests for alteration table on download tab
add more screenshots tests for alteration table on download tab


Former-commit-id: 95f3da6a33868d2714487fa73aab56e2cc4881c2
cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend