add rsvp option, redirect to auth when no access but resource exists

lectures/migrations/0016_alter_lecturegroup_user_groups.py

lectures/migrations/0017_merge_20230526_0027.py

.../0018_alter_lecturegroup_options_lecturegroup_priority.py

...igrations/0019_alter_lecturegroup_user_groups_and_more.py

lectures/models.py

lectures/templates/lectures/view_lecture.html

lectures/templatetags/rsvp.py

lectures/urls.py

lectures/views.py

package-lock.json

package.json

static_src/view_lecture.js

users/migrations/0009_alter_user_sso_username.py

users/models.py

webpack.config.js