Wizard: Add fetch and error state or target environments

This renders an empty state with a spinner when fetching target environments and alert when there's an issue.

src/test/Components/CreateImageWizard/steps/Services/Services.test.tsx

@@ -360,5 +360,3 @@ describe('Services edit mode', () => {
     expect(receivedRequest).toEqual(expectedRequest);
   });
 });
-
-// TO DO 'Services step' -> 'revisit step button on Review works'