Bluetooth: Add initial mgmt_confirm_name support

This patch adds initial support for mgmt_confirm_name. It adds the
necessary tracking of the name state by extending the inquiry cache. The
actual name resolving operation (to be done once inquiry is finished) is
not yet part of this patch.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>