Only allow the phone number whitespace format output by libphonenumber

[baltpeter]

For the suggestions and in the company-json-generator, we format phone numbers using libphonenumber. But so far, we have also allowed additional spaces to be added.

This is quite annoying because it makes suggestion PRs much harder to read:

ad752a9#diff-2e2c693eeb489acb22a617dd6fe60a96dd1f1db5b2c04418157418d52b5e49d5R17-R18

And if you don't manually edit the PR (which is even more annoying), we will eventually end up with the libphonenumber formatting, anyway.

As such, I propose that we add a test that always enforces the libphonenumber formatting.