Bug 9169 - Wrap relator code in <span> to allow for CSS customization

Bug 9169 - Wrap relator code in <span> to allow for CSS customization

This patch adds <span class="relatorcode"> around the display of
relator codes in the OPAC and the staff client, and adds a space
before the bracket (" [relatorcode]") for readability.

To test, add custom CSS to OPACUserCSS and IntranetUserCSS and
view a record which includes relator code data. Suggested:

.relatorcode {
    background-color: rgb(230, 240, 242);
    border-radius: 3px 3px 3px 3px;
    color: rgb(51, 51, 51);
    display: inline-block;
    font-size: 75%;
    font-weight: normal;
    margin-left: 0.4em;
    padding: 0.1em 0.4em;
}

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>