Add testid to page header and fix org cypress tests

ui/cypress/e2e/orgs.test.ts

@@ -48,9 +48,11 @@ describe('Orgs', () => {
       cy.visit(`${orgRoute}/${body.id}/members`)
 
       cy.get('.renamable-page-title--title').click()
-      cy.get('.input-field')
-        .type(newName)
-        .type('{enter}')
+      cy.getByTestID('page-header').within(() => {
+        cy.getByTestID('input-field')
+          .type(newName)
+          .type('{enter}')
+      })
 
       cy.visit('/organizations')
 

ui/src/pageLayout/components/PageHeader.tsx

@@ -34,7 +34,7 @@ class PageHeader extends Component<Props> {
     }
 
     return (
-      <div className={this.className}>
+      <div className={this.className} data-testid="page-header">
         <div className="page-header--container">{this.children}</div>
       </div>
     )