Add client CLI version in stderr

[jpraynaud]

Why

In order to help debugging of the client CLI, we need to display the version used in the stderr output (which is used for machine to machine logs).

What

Display the client CLI version as the first entry in the stderr output of the commands.

How

• Move the --json attribute globally (and -v, ...)
• Add an entry with the version of the client CLI in the stderr output
• Make it available for all the commands of the CLI