feat: add override function to empty response mocks

[karlismelderis-mckinsey]

Status

READY

Description

In some cases we do want to assert received request even for empty response mock
for that UI tests can add assertions in MSW mock override function

this PR allows us to do such assertion even for empty response mock:

      server.use(
        getPetsControllerBulkUpdateMockHandler(
          async ({ request, params }) => {
            const body = await request.json();

            expect(params.id).toBe('2');

            expect(body).toEqual({
              cats: [],
            });
          },
        ),
      );