Add Angular v19 to the list of supported versions in dependencies.

Callbacks `onSuccess()` and `onError()` were called before `$items` w…

…as updated. `$items()` inside the callbacks had a non-updated value.

New fields:

* `$lastReadError`
* `$lastReadOneError`
* `$lastReadManyError`
* `$lastRefreshError`

In params structures, fields `readRequest` and `refreshRequest` are deprecated (will be removed in v5).
Use `read` and `refresh` instead.

New method: `fetchItem()`!

This method will check if the item exists in the collection and return it if it does.
If the item does not exist, the `request` argument will be used to fetch the item and add it to the collection.
If the option `fetchItemRequestFactory` is set, the `request` argument is optional.
If both are missing, the resulting Observable will throw an error.

`createEffect.forValue()` renamed to `getEffectFor()`.

Experimental method for `createEffect()`: `forValue()`, which takes a…

… value and returns an observable that will execute the effect when subscribed.

* New (experimental!) methods: `readFrom` and `readManyFrom`. Can be …

…called as part of constructor options.

* `EffectFnMethods` renamed to `EffectObservables`, and lost methods `next`, `error` and `complete` - the same functionality with a less ambiguous API can be achieved with `EffectListeners`. This API is considered stable now.

* Use `untracked()` every time when reactive context should not be af…

…fected;

* Use `take(1)` instead of `first()` to prevent `no elements in sequence` exception.

Improved API for `createEffect()` listeners, introduced in v4.1.1.

### 4.1.1

`createEffect()` now returns not just a function, but a function with methods! :)
API is experimental and might change,  so it's documented only here for now.

In your store:

```ts
import { createEffect } from './create-effect';

class Store extends Collection<Item> {
  readonly changeZipCode = createEffect<string>(_ => _.pipe(
    // code to change zipcode
  ));
}
```

In your component:

```ts
class Component {
  store = inject(Store);
  dialog = inject(Dialog);

  changeZipCode(zipCode: string) {
    this.store.changeZipCode.nextValue(() => this.dialog.close());
    this.store.changeZipCode(zipCode);
  }
}
```

In this example, the dialog window will be closed only *after* the service response, and only if it was successful.

Alongside nextValue, there are other methods:
```ts
export type EffectFnMethods = {
  nextValue: (fn: ((v: unknown) => void)) => void,
  nextError: (fn: ((v: unknown) => void)) => void,
  onNextValue(): Observable<unknown>,
  onNextError(): Observable<unknown>,
};
```

Internally, values and errors will not be saved in memory if you don't use these methods.