Fix twenty cli (#15997)

As title

fixes "app add" and "app init" commands
adds tests

packages/twenty-cli/src/utils/__tests__/get-serverless-function-base-file.spec.ts

@@ -0,0 +1,34 @@
+import { getServerlessFunctionBaseFile } from '../get-serverless-function-base-file';
+
+describe('getServerlessFunctionBaseFile', () => {
+  it('should render proper file', () => {
+    expect(
+      getServerlessFunctionBaseFile({
+        name: 'serverless-function-name',
+        universalIdentifier: '71e45a58-41da-4ae4-8b73-a543c0a9d3d4',
+      }),
+    )
+      .toBe(`import { type ServerlessFunctionConfig } from 'twenty-sdk/application';
+
+export const main = async (params: {
+  a: string;
+  b: number;
+}): Promise<{ message: string }> => {
+  const { a, b } = params;
+
+  // Rename the parameters and code below with your own logic
+  // This is just an example
+  const message = \`Hello, input: \${a} and \${b}\`;
+
+  return { message };
+};
+
+export const config: ServerlessFunctionConfig = {
+  universalIdentifier: '71e45a58-41da-4ae4-8b73-a543c0a9d3d4',
+  name: 'serverless-function-name',
+  timeoutSeconds: 5,
+};
+
+`);
+  });
+});