WARNING: breaks compatibility with previous versions (RING and DHT)

* OpenDHT uses msgpack library for serialization (added to contrib)
* OpenDHT uses GCM-AES+RSA for encryption (instead of RSA)
* adapts ringaccount to follow these API changes

Issue: #78264
Change-Id: I12744990d51e8f9022007ba59472d74aec89caeb