Fix data URL and metadata of vivos dataset
_The documentation is not available anymore as the PR was closed or merged._
After contacting the authors of the VIVOS dataset to report that their data server is down, we have received a reply from Hieu-Thi Luong that their data is now hosted on Zenodo: https://doi.org/10.5281/zenodo.7068130

This PR updates their data URL and some metadata (homepage, citation and license).

Fix #4936.