There are no samples for Data Catalog clients in the repository #2141

Describe the issue

Data Catalog is a new product in GCP's Big Data family. There is an initial version for its cloud client library publicly available (https://googleapis.github.io/google-cloud-python/latest/datacatalog/gapic/v1beta1/api.html), but not samples for it in this repository.

As an early adopter of this product, I would like to contribute by creating the datacatalog/cloud-client folder in repo's root and adding samples there.