tasks: Add new zanata client
tasks: Add new zanata client

`zanata-client` does not exist in Fedora 31. Also it requires a lot of
java deps.
`python3-zanata-client` provides `zanata` cli tool.
For now lets have both until all projects migrate to this new zanata
tool.

Closes #298

cockpit-project/cockpituous,cockpit-project/cockpituous