Add .prettierrc.json and refactor test files for improved formatting consistency:

- Introduced `.prettierrc.json` to enforce consistent code formatting across the project.
- Updated unit and e2e test files to address formatting issues, improve readability, and ensure alignment with the new Prettier configuration.

tests/unit/department-self-serve-enabled.spec.js

@@ -30,10 +30,7 @@ describe("department self-serve enabled management", () => {
     const enabled = await getDepartmentSelfServeEnabled("12");
 
     expect(enabled).toBe(true);
-    expect(mocks.authenticatedRequest).toHaveBeenCalledWith(
-      "/departments/self-serve/enabled?id=12",
-      "GET"
-    );
+    expect(mocks.authenticatedRequest).toHaveBeenCalledWith("/departments/self-serve/enabled?id=12", "GET");
   });
 
   it("normalizes false-like enabled responses", async () => {