[Server Integration tests] Enrich integration GraphQL API tests (#7699)

### Description

- We are using gql instead of strings to be able to see the graphql code
highlighted

### Demo


![](https://assets-service.gitstart.com/28455/d06016b9-c62c-4e0d-bb16-3d7dd42c5b6b.png)

Fixes #7526

---------

Co-authored-by: gitstart-twenty <gitstart-twenty@users.noreply.github.com>
Co-authored-by: Charles Bochet <charles@twenty.com>
Co-authored-by: Charles Bochet <charlesBochet@users.noreply.github.com>

packages/twenty-server/test/integration/utils/create-app.ts

@@ -0,0 +1,45 @@
+import { NestExpressApplication } from '@nestjs/platform-express';
+import { Test, TestingModule, TestingModuleBuilder } from '@nestjs/testing';
+
+import { AppModule } from 'src/app.module';
+
+interface TestingModuleCreatePreHook {
+  (moduleBuilder: TestingModuleBuilder): TestingModuleBuilder;
+}
+
+/**
+ * Hook for adding items to nest application
+ */
+export type TestingAppCreatePreHook = (
+  app: NestExpressApplication,
+) => Promise<void>;
+
+/**
+ * Sets basic integration testing module of app
+ */
+export const createApp = async (
+  config: {
+    moduleBuilderHook?: TestingModuleCreatePreHook;
+    appInitHook?: TestingAppCreatePreHook;
+  } = {},
+): Promise<NestExpressApplication> => {
+  let moduleBuilder: TestingModuleBuilder = Test.createTestingModule({
+    imports: [AppModule],
+  });
+
+  if (config.moduleBuilderHook) {
+    moduleBuilder = config.moduleBuilderHook(moduleBuilder);
+  }
+
+  const moduleFixture: TestingModule = await moduleBuilder.compile();
+
+  const app = moduleFixture.createNestApplication<NestExpressApplication>();
+
+  if (config.appInitHook) {
+    await config.appInitHook(app);
+  }
+
+  await app.init();
+
+  return app;
+};