Using long-term static public keys, it is possible to identify the
recipient of a handshake message. Add a new UAT where such keys can be
configured. Allow private keys to be configured as well since this
enables decryption of the Initiation handshake message.
Bug: 15011
Change-Id: I0d4df046824eac6c333e0df75f69f73d10ed8e5e
Reviewed-on: https://code.wireshark.org/review/28988
Reviewed-by: Anders Broman <a.broman58@gmail.com>