feat: add pwa handling

.gitignore

.gitlab-ci.yml

Dockerfile

angular.json

nginx/dev.conf

ngsw-config.json

package-lock.json

package.json

proxy.conf.json

src/app/app.component.ts

src/app/app.module.ts

src/app/page/page.component.ts

src/app/services/notification.service.ts

src/app/services/update.service.ts

src/assets/icons/icon-128x128.png

src/assets/icons/icon-144x144.png

src/assets/icons/icon-152x152.png

src/assets/icons/icon-192x192.png

src/assets/icons/icon-384x384.png

src/assets/icons/icon-512x512.png