Improve namespace extraction from hook/HOC

[nicegamer7]

Why am I submitting this PR

While working on localizing our project, we used some code along the lines of the following:

export default withTranslation(undefined, { withRef: true })(
  ...
);

This resulted in the related strings being extracted under the "undefined" namespace, rather than using the default which is expected. Similarly, using a variable causes the strings to be extracted to a namespace that matches the name of that variable, rather than a warning being emitted.

Does it fix an existing ticket?

No.

Checklist

• [x] only relevant code is changed (make a diff before you submit the PR)
• [x] tests are included and pass: yarn test (see details here)
• [ ] documentation is changed or added

[karellm]

Thanks for the thorough PR! It is deployed as 8.2.0