Add missing bits to ChannelableCombined and SubscribableTypes for v1 migration

[nlopezgi]

Problem

The type migration from v1beta1 -> v1 (#3336) is missing some bits:

• The ChannelableCombined is a type that represents a skeleton type wrapping Subscribable and Addressable of both v1alpha1 and v1beta1 duck types. This type also needs a Subscribable and Addressable for v1.
• The SubscribableTypes also has fields that are only for v1beta1 and need to support v1.

Blocking: #3789

Exit Criteria
Its possible to continue with migration of channels in #3789

See also

#3584 (comment)

[nlopezgi]

/assign