http请求url参数包含+号，被解析为空格

https://github.com/angular/angular/issues/11058

@Injectable()
export class EncodeUrlParamsSafelyInterceptor implements HttpInterceptor, HttpParameterCodec {
  intercept(req: HttpRequest, next: HttpHandler): Observable> {
    const newParams = new HttpParams({
      fromString: req.params.toString(),
      encoder: this,
    });

    return next.handle(req.clone({
      params: newParams,
    }));
  }

  encodeKey(key: string): string {
    return encodeURIComponent(key);
  }

  encodeValue(value: string): string {
    return encodeURIComponent(value);
  }

  decodeKey(key: string): string {
    return decodeURIComponent(key);
  }

  decodeValue(value: string): string {
    return decodeURIComponent(value);
  }
}