I've changed the logic so that AjaxHelpers keeps
track of which requests have not yet had mock
responses sent. This ensures that every response
is handled before moving on to the next one,
rather than always handling the last request.
My intention is that this won't allow bugs to creep
in where a request isn't fired and instead the test
responds to an old request. It also should ensure
that extra events aren't accidentally fired.
This commit implements STUD-1490, allowing creation of components
on the container page. It also enables the delete and duplicate
buttons now that new content can be created that would benefit.
Note that it also creates shared functionality for adding components,
and refactors the unit page to use it too.
