TNL-1900 Implement teams header component

...angoapps/teams/static/teams/js/spec/teams_factory_spec.js

lms/djangoapps/teams/static/teams/js/teams_tab_factory.js

lms/djangoapps/teams/static/teams/js/views/teams_tab.js

lms/djangoapps/teams/templates/teams/teams.html

lms/djangoapps/teams/views.py

lms/static/js/components/header/models/header.js

lms/static/js/components/header/views/header.js

lms/static/js/spec/components/header/header_spec.js

lms/static/js/spec/main.js

lms/static/js_test.yml

lms/templates/components/header/header.underscore