Fix the module path for MU non-acceptance tests

[ppcano]

Closes #8363

It set correctly the module path of the MU tests; given the following test file /src/utils/unit-test:

Before -> $packageName/tests/utils/unit-test
Now -> $packageName/src/utils/unit-test

The fix solves relative imports within the test file. The PR includes an unit test:

import { module, test } from 'qunit';
import stringFn from './string';

 module('Unit | Utility | string', function() {
  ...
 });

[rwjblue]

Awesome, thank you!