util: Added missing zipfile import.

refs #16209
update_course_list: Now using lxml as parser.

We also added lxml to the requirements file.

refs #16209
config: Updated config so app folder is correct.

refs #16209
More sane way to get correct project_path.

refs #16209
Merge branch 'bug/16209' into develop
controllers: Fixed type on current_app.

refs #16215
install_course: Added missing vars/funcs.

Was missing install_course_to_site from util.py and the filtered courses list,
which was probably lost somewhere in some merge conflicts.

refs #16215