the Icon and Button APIs already escape attributes, fixes #1797

app/views/studiengaenge/informationen/showdegree.php

app/views/studiengaenge/informationen/showstudycourse.php

app/views/studiengaenge/stgteilbezeichnungen/index.php

app/views/studiengaenge/studiengaenge/aufbaustg_table.php

app/views/studiengaenge/studiengaenge/studiengaenge.php

app/views/studiengaenge/studiengaenge/studiengangteile.php

app/views/studiengaenge/studiengangteile/details_grouped.php

app/views/studiengaenge/studiengangteile/index.php

app/views/studiengaenge/versionen/abschnitte.php

app/views/studiengaenge/versionen/details_abschnitt.php

app/views/studiengaenge/versionen/versionen.php

templates/calendar/entries/icons.php

templates/mail/notification_html.php

templates/tabs.php