Angular 19 - Streamlining Data Retrieval with Experimental Resource and rxResource APIs

Angular 19 introduces two experimental APIs, `resource` and `rxResource`, for simplifying asynchronous data retrieval using Signals. The `resource` API uses Promises while `rxResource` leverages Observables. Both return a `WritableResource` object with status signals (Loading, Resolved, Reloading, Local, Error). Key features covered include local data updates via `update()`, manual refresh with `reload()`, reactive loading by binding signals to the `request` parameter, race condition handling with `abortSignal`, multiple signal dependencies, and reusable resource functions. The `rxResource` variant differs by being Observable-based, not requiring an abortSignal, and only consuming the first emitted value.