A subscriber issues a UNSUBSCRIBE_ANNOUNCES message to a publisher indicating
it is no longer interested in ANNOUNCE, UNANNOUNCE and PUBLISH messages for the
specified track namespace prefix.
The format of UNSUBSCRIBE_ANNOUNCES is as follows:
UNSUBSCRIBE_ANNOUNCES Message {
Type (i) = 0x14,
Length (16),
Track Namespace Prefix (tuple)
}
-
Track Namespace Prefix: As defined in Section 8.27.