[typescript-angular] Add support for Angular’s experimental httpResource

[gonzalad]

This PR adds support for Angular’s experimental httpResource API (see issue #21263).

Support is currently limited to GET requests, following Angular’s official recommendation:

TIP: Avoid using httpResource for mutations like POST or PUT.
Instead, prefer directly using the underlying HttpClient APIs.

All non-GET methods continue to rely on RxJS.

Tests

A new integration test was introduced:
TypescriptAngularResourceIntegrationTest.

As with the other TypeScript integration tests, it is currently disabled in the pushed version.

Generated API (example)

Parameters accept either signal or non-signal types, enabling flexible usage depending on the consumer’s needs.

Single GET example:

public lireEntreprise(id: Signal<string> | string, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<Entreprise>;
public lireEntreprise(id: Signal<string> | string, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<HttpResponse<Entreprise>>;
public lireEntreprise(id: Signal<string> | string, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<HttpEvent<Entreprise>>;
public lireEntreprise(id: Signal<string> | string, reportProgress: boolean = false, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<any> {

List GET example:

public listerEntreprises(status: Signal<Array<'available' | 'pending' | 'sold'>> | Array<'available' | 'pending' | 'sold'>, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<Array<Entreprise>>;
public listerEntreprises(status: Signal<Array<'available' | 'pending' | 'sold'>> | Array<'available' | 'pending' | 'sold'>, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<HttpResponse<Array<Entreprise>>>;
public listerEntreprises(status: Signal<Array<'available' | 'pending' | 'sold'>> | Array<'available' | 'pending' | 'sold'>, reportProgress?: boolean, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<HttpEvent<Array<Entreprise>>>;
public listerEntreprises(status: Signal<Array<'available' | 'pending' | 'sold'>> | Array<'available' | 'pending' | 'sold'>, reportProgress: boolean = false, options?: {httpHeaderAccept?: 'application/json', context?: HttpContext, transferCache?: boolean}): HttpResourceRef<any> {

Cheers,
Adrian

N.B. This PR targets typescript, so I mention the technical comitee @TiFu (2017/07) @taxpon (2017/07) @sebastianhaas (2017/07) @kenisteward (2017/07) @Vrolijkx (2017/09) @macjohnny (2018/01) @topce (2018/10) @akehir (2019/07) @petejohansonxo (2019/11) @amakhrov (2020/02) @davidgamero (2022/03) @mkusaka (2022/04) @joscha (2024/10)

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