Bug 37779: Fix forms that POST without an op in tag moderation

Bug 37779: Fix forms that POST without an op in tag moderation

We intend not to have forms with method="post" without an op variable (so we
can check that the op starts with "cud-" as part of the CSRF protection), but
because of bug 37728 some were missed.

There are two in tags/review.tt: the filters for term, status, reviewer, and
dates, which are better as a GET since you can then bookmark and link to a
particular set of filters, and the no-JavaScript fallback for checking whether
a term has been approved or rejected, which currently doesn't work at all,
but with a working op param then works just fine as a GET.

Test plan:

If you have to use Chrome, you're on your own for the disabling JavaScript
and getting rid of the body {display: none !important} style rule, my plan
uses Firefox's devtools to do it

 1. Without the patch, Tools - Tags - change the filter from the default
    status "pending" to "all", Apply, and bookmark the page
 2. Open your bookmark, note that it's status "pending"
 3. You can't test the no-JS fallback for term testing since it doesn't
    work, so apply patch and restart_all
 4. Tools - Tags - change the filter from the default status "pending"
    to "all", Apply, and bookmark the page
 5. Open your bookmark, note that it's status "all"
 6. You need a couple of tags to test the Test feature, so open the OPAC,
    log in, search for any record and add the tags approveme, rejectme
 7. Back in Tools - Tags, click the Reject button to reject rejectme
 8. In the Check lists input, test that approveme shows "approveme is
    permitted!" and rejectme shows "rejectme is prohibited!"
 8. Now to disable JavaScript, open Firefox's More tools - Web Developer
    Tools. You're going to need the Style Editor, so if it's not visible
    you'll want to enable it in Settings in the next step
 9. Top bar, right side, there's a three-dots menu, with an option for
    Settings. In Advanced settings, click the checkbox for Disable JavaScript
    (which as hovering the * says, is only for that tab and only until you
    close the tab or the toolbox).
10. Checking Disable JavaScript turned your page to blank white, so go to
    the Style Editor, where the first thing, already selected, is an inline
    style sheet with the rule "body {display: none !important}" - select all
    the text of the rule and delete it, which you'll have to do on every
    page load
11. In the Check lists input, test that approveme still shows "approveme
    is permitted!" (after you delete the display: none !important rule, and
    with a rather annoying message about "Tested 1 Term(s)." replacing the
    list of terms).

Sponsored-by: Chetco Community Public Library
Signed-off-by: Sukhmandeep Benipal <sukhmandeep.benipal@inLibro.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>