Add auth, core and shared modules

client/package.json

client/src/app/app.component.html

client/src/app/app.module.ts

client/src/app/auth/auth.action.ts

client/src/app/auth/auth.effects.ts

client/src/app/auth/auth.module.spec.ts

client/src/app/auth/auth.module.ts

client/src/app/auth/auth.reducer.ts

client/src/app/auth/auth.selector.ts

client/src/app/auth/init.keycloak.ts

client/src/app/auth/user-profile.model.ts

client/src/app/core/components/nav.component.html

client/src/app/core/components/nav.component.ts

client/src/app/core/containers/app.component.html

client/src/app/core/containers/app.component.scss

client/src/app/core/containers/app.component.spec.ts

client/src/app/core/containers/app.component.ts

client/src/app/core/core.module.ts

client/src/app/shared/shared.module.ts

client/src/environments/environment.ts