We were repeating the same code over and over (with a few variants) to
setup tests which require an administrator. We can use a tag and
simplify the code.
We weren't using `foundation()` in these cases, so after flagging a
debate or a comment, we had to reload the page before we could unflag
it.
We're also adding a test for the fix in commit ea85059d. This test shows
it's necessary to filter the elements with JavaSctipt using `first()` if
we want the same code to work with comments.
Co-Authored-By: taitus <sebastia.roig@gmail.com>
