test: Adding Percy Snapshot on VTK, PDF and Microscopy tests (#1059)

* Adding Percy Snapshot on VTK, PDF and Microscopy tests

* Small improvement to always click on first search result

* Wait for search result

* Added timouts all over the code to avoid intermitted failures in CI

* Increasing Default Timeout and other configs

* Cleaning up the code

* try force enabling gpu

* Try custom executor with newer version of chrome

* Fix based on review comments

* Increased minimum thumbnails expected on VTK test

* Fix config validation

* Make sure we're using the chrome browser

platform/viewer/cypress/integration/pwa/OHIFExtensionHTML.spec.js

@@ -1,7 +1,7 @@
 describe('OHIF HTML Extension', () => {
   before(() => {
     cy.openStudy('Dummy');
-    cy.expectMinimumThumbnails(1);
+    cy.expectMinimumThumbnails(5);
   });
 
   it('checks if series thumbnails are being displayed', () => {
@@ -14,6 +14,7 @@ describe('OHIF HTML Extension', () => {
   it('drags and drop a SR thumbnail into viewport', () => {
     cy.get('[data-cy="thumbnail-list"]')
       .contains('SR')
+      .first()
       .drag('.viewport-drop-target');
 
     cy.get(':nth-child(2) > h1').should(