[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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[bhahn57570]

Hello,
Now that httpResource in not anymore in experimental mode is this branch going to be merged or not ?

Thanks

[wing328]

please resolve the merge conflicts in this PR or open a new PR based on this one instead. thank you

[aggroman]

no empty line

[aggroman]

indent seem like not to be proper generated

[aggroman]

indent issue here as well

[aggroman]

is it intended to ignore observable option for GET requests, when useHttpResource === true?
if so, then developers would not have an option to keep previous implementations as they are and forced to use httpResource everywhere. my proposal would be to allow both, when useHttpResource is available.

return httpResource when input is provided as Signal, otherwise Observable