Merge pull request 'OZG-4321-Login' (#443) from OZG-4321-Login into master

alfa-client/.gitignore

alfa-client/apps/admin/src/app/app.component.html

alfa-client/apps/admin/src/app/app.component.spec.ts

alfa-client/apps/admin/src/app/app.component.ts

alfa-client/apps/admin/src/app/app.config.ts

alfa-client/apps/admin/src/app/app.module.ts

alfa-client/apps/admin/src/common/auth/auth.service.spec.ts

alfa-client/apps/admin/src/common/auth/auth.service.ts

...on-container/user-profile-button-container.component.html

...container/user-profile-button-container.component.spec.ts

...tton-container/user-profile.button-container.component.ts

alfa-client/apps/admin/src/main.ts

.../postfach-container/postfach-form/postfach.formservice.ts

alfa-client/libs/authentication/.eslintrc.json

alfa-client/libs/authentication/README.md

alfa-client/libs/authentication/jest.config.ts

alfa-client/libs/authentication/project.json

alfa-client/libs/authentication/src/index.ts

...libs/authentication/src/lib/authentication.module.spec.ts

...ient/libs/authentication/src/lib/authentication.module.ts