Use wait_for_requests for checking Vue resource and $.ajax requests [CE]
Makes wait_for_ajax
check Vue resource and $.ajax
requests and remove existing wait_for_vue_resource
helper.
This will probably make our test-suite more stable as an extra benefit.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/31946 and https://gitlab.com/gitlab-org/gitlab-ce/issues/31555
EE MR: gitlab-ee!1923
Edited by Oswaldo Ferreir