Adapt react-client to use the real backend API (#1545)

Co-authored-by: Philip Molares <philip.molares@udo.edu>
Co-authored-by: Tilman Vatteroth <git@tilmanvatteroth.de>

src/api/common/api-request-builder/get-api-request-builder.ts

@@ -0,0 +1,23 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { ApiRequestBuilder } from './api-request-builder'
+import type { ApiResponse } from '../api-response'
+
+/**
+ * Builder to construct a GET request to the API.
+ *
+ * @param ResponseType The type of the expected response.
+ * @see {ApiRequestBuilder}
+ */
+export class GetApiRequestBuilder<ResponseType> extends ApiRequestBuilder<ResponseType> {
+  /**
+   * @see {ApiRequestBuilder#sendRequest}
+   */
+  sendRequest(): Promise<ApiResponse<ResponseType>> {
+    return this.sendRequestAndVerifyResponse('GET', 200)
+  }
+}