It doesn't make a ton of sense for disablement to be communicated as an AUM, because
any failure in the AUM or chain mechanism will mean disablement wont function.
Instead, tracking of the disablement secrets remains inside the state machine, but
actual disablement and communication of the disablement secret is done by the caller.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Following the pattern elsewhere, we create a new tka-specific types package for the types
that need to couple between the serialized structure types, and tka.
Signed-off-by: Tom DNetto <tom@tailscale.com>
