Split register-template and make it configurable

...s/alsijil/templates/alsijil/partials/person_overview.html

...il/templates/alsijil/partials/register_abbreviations.html

...sijil/templates/alsijil/partials/register_coursebook.html

...ps/alsijil/templates/alsijil/partials/register_cover.html

...il/templates/alsijil/partials/register_members_table.html

...lsijil/partials/register_teachers_and_subjects_table.html

...s/apps/alsijil/templates/alsijil/print/full_register.html