[feat] Implement piping from one command to the next

[Javier G. Sogo]

With piping, you can search for a reference and then get the JSON to populate the database:

jfrog conan-center search <repo>  --ref-name=b2 --only-latest | jfrog conan-center index-reference --force

and it will iterate references returned by the search command and call index-reference with each of them.