A simple application that establishes DTLS connection(s) and
sends/receives datagrams. Class DtlsAssociation is
essentially a QUdpSocket|QDtls pair: it initiates a handshake,
handles timeouts and errors. After establishing an encrypted
connection it sends messages to the server and processes responses.
Task-number: QTBUG-67596
Change-Id: I92d481b7dfd2459e6a93c754b338a2e897a7feaf
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
