Merge branch 'progressive-web-application' into 'develop'

api/config/settings/common.py

api/funkwhale_api/common/middleware.py

api/funkwhale_api/instance/urls.py

api/funkwhale_api/instance/views.py

api/tests/common/test_middleware.py

api/tests/instance/test_views.py

front/package.json

front/src/App.vue

front/src/components/ServiceMessages.vue

front/src/components/audio/Player.vue

front/src/main.js

front/src/registerServiceWorker.js

front/src/service-worker.js

front/src/store/ui.js

front/vue.config.js

front/yarn.lock