Bug 37056: Mount a new intranet_svc api to avoid redirects

Bug 37056: Mount a new intranet_svc api to avoid redirects

When an unauthorized call to svc is made, we use the ErrorDocument middleware to respond with an HTML
page. The API doens't do this, it simply returns its status. We should mount the svc as its own app to avoid
the redirect to HTML for unauthorized responses

To test:
1 - Create a report
2 - Add to IntranetUserJs:
    $(document).ready(function() {
      // Your report ID
      var reportId = '492';

      // Fetch the report
      $.get('/cgi-bin/koha/svc/report?id=' + reportId, function(data) {
        console.log('Kaboom');
      });
    });
3 - Log out
4 - Attempt to login
5 - KO
6 - Apply patch
7 - Reset all (or copy the necessary changes to your plack/apache files)
8 - Generate report and update user js again
8 - Logout, login
9 - Success!

Signed-off-by: Brendan Lawlor <blawlor@clamsnet.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>