avoid use of `tfoot` in nested tables in MVV, fixes #90

app/views/fachabschluss/kategorien/details.php

app/views/fachabschluss/kategorien/index.php

app/views/module/module/details.php

app/views/module/module/modulteil_lvg.php

app/views/studiengaenge/informationen/degree.php

app/views/studiengaenge/informationen/index.php

app/views/studiengaenge/stgteilbezeichnungen/index.php

...ews/studiengaenge/studiengaenge/stgteil_bezeichnungen.php

app/views/studiengaenge/studiengaenge/studiengangteile.php

app/views/studiengaenge/versionen/abschnitte.php

app/views/studiengaenge/versionen/details_abschnitt.php

resources/assets/stylesheets/less/mvv.less

resources/assets/stylesheets/less/tables.less