Support for DC106 confirm/pair

[hvandenesker]

To pair a (virtual) remote for home assistent I had to buy an old windows laptop to run rfxmngr.
This was ackward, while I guess it could be part of ha itself. For RollerTrolDevice we need
{code}
def send_pair(self, transport):
""" Send a 'Pair/Confirm' command using the given transport """
pkt = lowlevel.RollerTrol()
pkt.set_transmit(
self.subtype,
self.cmndseqnbr,
self.id_combined,
self.unitcode,
0x03
)
self.cmndseqnbr = (self.cmndseqnbr + 1) % 5
transport.send(pkt.data)
{code}
related: https://community.home-assistant.io/t/solved-rfxtrx-cover-t6-blinds-not-working/18914

[elupus]

Think you can provide a pull request for this? (with tests)