The `HttpParamsOptions` was not documented or included in the public API even
though it is a constructor argument of `HttpParams` which is a part of the
public API. This commit adds the `HttpParamsOptions` into the exports, thus
making it a part of the public API.
Resolves#20276
PR Close#35829
Fixes#23023.
When a HTTP Interceptor injects HttpClient it causes a DI cycle. This fix is to use Injector to lazily inject HTTP_INTERCEPTORS while setting up the HttpHandler on the server so as to break the cycle.
PR Close#24229
HttpClient is an evolution of the existing Angular HTTP API, which exists
alongside of it in a separate package, @angular/common/http. This structure
ensures that existing codebases can slowly migrate to the new API.
The new API improves significantly on the ergonomics and features of the legacy
API. A partial list of new features includes:
* Typed, synchronous response body access, including support for JSON body types
* JSON is an assumed default and no longer needs to be explicitly parsed
* Interceptors allow middleware logic to be inserted into the pipeline
* Immutable request/response objects
* Progress events for both request upload and response download
* Post-request verification & flush based testing framework