Bug 34343: Update style of fixed footer navbar in Z39.50 searches

Bug 34343: Update style of fixed footer navbar in Z39.50 searches

We use a Bootstrap fixed navbar in the footer of two pages: the popup
Z39.50 searches in cataloging and authorities. The style of these
footers needs to be udpated for the new staff interface design.

This patch also changes the style of the "cancel" controls in these
footers from links to buttons. The popup window in cataloging has been
adjusted to be the same size as the one in authorities.

To test, apply the batch and rebuild the staff interface CSS.

- Go to Cataloging -> New from Z39.50/SRU.
  - In the popup window, the form should fit comfortably in the window.
  - The footer should be white with a grey border at the top, with
    Bootstrap-styled buttons aligned to the right.
- Perform the same test in Authorities -> New from Z39.50/SRU
- Install and enable an additional translation so that you can confirm
  that the language-selection footer still has the correct style.

Signed-off-by: Caroline Cyr La Rose <caroline.cyr-la-rose@inlibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 3ac122f47d18fe527c6c789a664d4c2b401f5e4c)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>