usertools: add client script for telemetry

usertools: add client script for telemetry

This patch adds a python script which can be used as a demo
client. The script is interactive and will allow the user to
register, request statistics, and unregister.

To run the script, an argument for the client file path must
be passed in: "python telemetry_client.py <file_path>".

This script is useful to see how the Telemetry API for DPDK
is used, and how to make the initial connection.

Signed-off-by: Ciara Power <ciara.power@intel.com>
Signed-off-by: Brian Archbold <brian.archbold@intel.com>
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>