Bug 37833: Incorrect logic controlling display of OPAC language selection menus

Bug 37833: Incorrect logic controlling display of OPAC language selection menus

This patch corrects the logic around how the OPAC language menus are
displayed. Because the footer and header lanugage menus have been
combined into one, the logic for whether the menu should appear has to
live outside the include. The patch also makes corrections to ensure
that the footer menu appears even if the footer language menu is hidden.

NOTE: This patch contains whitespace changes, so please view the diff
accordingly.

To test you should have at least one additional language installed.

- Apply the patch and make sure the OPACLanguages system preference has
  more than one language checked.
- Set opaclanguagesdisplay to "Allow."
- In the OPAC, test that the various settings of the
  OpacLangSelectorMode preference work correctly (only top, only footer,
  both top and footer).
- Test with OPACReportProblem on and off, and CookieConsent on and off.
- Test with OPACReportProblem or CookieConsent enabled and
  opaclanguagesdisplay disabled.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>