Bug 22672: Change <i> to <em> and <b> to <strong> in templates, includes, xslt

Bug 22672: Change <i> to <em> and <b> to <strong> in templates, includes, xslt

This patch attempts to replace <i> with <em> AND <b> with <strong> in
order to more accessible to screen readers. This patch makes no attempt
to change Font Awesome icons which typically use <i>. I found templates,
includes and XSLT by using 'git grep ‘<b>’
koha-tmpl/opac-tmpl/bootstrap/en/' and git grep ‘<i>’
koha-tmpl/opac-tmpl/bootstrap/en/

TEST PLAN:
There should be no visible difference on the changed pages. The files
changed are:
koha-tmpl/opac-tmpl/bootstrap/en/includes/holds-table.inc
koha-tmpl/opac-tmpl/bootstrap/en/includes/opac-note.inc
koha-tmpl/opac-tmpl/bootstrap/en/modules/clubs/enroll.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-auth-MARCdetail.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-authoritiessearchresultlist.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-browser.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-course-details.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-downloadshelf.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-messaging.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-opensearch.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-overdrive-search.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-privacy.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-results-grouped.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-results.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-review.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-shareshelf.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-shelves.tt
koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-user.tt
koha-tmpl/opac-tmpl/bootstrap/en/xslt/MARC21slim2OPACResults.xsl
koha-tmpl/opac-tmpl/bootstrap/en/xslt/NORMARCslim2OPACResults.xsl
koha-tmpl/opac-tmpl/bootstrap/en/xslt/UNIMARCslim2OPACResults.xsl
koha-tmpl/opac-tmpl/xslt/OAI.xslt

Read the changes and make sure everything looks correct, try to visit as
many pages as possible and confirm that everything looks as it should.
grep around for cases of <b> or <i> that I could have missed.

Signed-off-by: Timothy Alexis Vass <timothy_alexis.vass@ub.lu.se>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>