Extract core functionality from `libs/angular` to allow teams to depend on `libs/ui-common` instead.
Moves the following functionality to `ui-common`.
- `I18nPipe`. `libs/angular` still has an old copy but `components` depends on the new variant from `ui-common`.
- `safeProvider`, `SafeProvider` and `SafeInjectionToken`. `libs/angular`re-exports these to avoid needing to update all consumers.
Update all libs to use explicit dependencies rather than relying on tsconfig.libs.json. This allows us to more easily understand the dependencies between libs and prevent users from accidentally adding new dependencies.
We still use tsconfig.libs (now renamed tsconfig.spec) for tests.
