hci: Add Connected Isochronous Sets related commands and events

Patch introduces initial support for handling isochronous channels HCI
commands, event, responses. This initial patch add all the HCI command
and event codes as defined in the spec but in implementation it is
limited to Connected Isochronous Sets (CIS) only. Broadcast related
functionality will be added in future work.

Bug: 150670922
Tag: #feature
Test: compilation
Sponsor: jpawlowski
Change-Id: I06a0ad7a62a14216c6a8b8aef2cf3e1b8c85e0f0