feat(samples): add basic discovery sample with mqtt5 client

[sperka]

Issue #, if available:

Description of changes:
Added basic discovery example for MQTT5. MQTT5 client implementation has major changes compared to v311, hence, an example would benefit customers to see how to connect with the MQTT5 client using discovery.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[bretambrose]

This is really nice. I'll see about getting it merged; the only possible hangup is there may be a "well the other SDKs should get a corresponding sample too" which might slow things down a bit.