feat(OHIFv3):Add static e2e data (#2665)

This change wraps the E2E test data into a github repository, which is then included in the test builds as static data.
That makes running the e2e tests as simple as:
yarn test:e2e:server
yarn test:e2e

without any need to have docker etc installed/running.

platform/viewer/cypress/support/commands.js

@@ -202,10 +202,17 @@ Cypress.Commands.add('waitDicomImage', (timeout = 50000) => {
 
             element.addEventListener('cornerstoneimagerendered', onEvent);
           };
-          $cornerstone.events.addEventListener(
-            'cornerstoneelementenabled',
-            onEnabled
-          );
+          const enabledElements = $cornerstone.getEnabledElements();
+          if (enabledElements && enabledElements.length && !enabledElements[0].invalid) {
+            // Sometimes the page finishes rendering before this gets run,
+            // if so, just resolve immediately.
+            resolve();
+          } else {
+            $cornerstone.events.addEventListener(
+              'cornerstoneelementenabled',
+              onEnabled
+            );
+          }
         });
       });
   }