test: Try workaround for percy snapshot (#1084)

platform/viewer/cypress/integration/common/OHIFStandaloneViewer.spec.js

@@ -5,7 +5,7 @@ describe('OHIFStandaloneViewer', () => {
 
   it('loads route with at least 2 rows', () => {
     cy.screenshot();
-    cy.percySnapshot();
+    cy.percyCanvasSnapshot('Study List');
 
     cy.get('#studyListData tr')
       .its('length')

platform/viewer/cypress/integration/common/OHIFStudyViewer.spec.js

@@ -12,7 +12,7 @@ describe('OHIF Study Viewer Page', () => {
 
   it('checks if series thumbnails are being displayed', () => {
     cy.screenshot();
-    cy.percySnapshot();
+    cy.percyCanvasSnapshot('Series Thumbnails');
 
     cy.get('[data-cy="thumbnail-list"]')
       .its('length')