- Allow client-side to server-side apply upgrade.
Ensure that a user can change management of an object from client-side apply to
server-side apply without conflicts.
- Allow server-side apply to client-side downgrade.
For an object managed with client-side apply, a user may upgrade to
managing the object with server-side apply, then decide to downgrade.
We can support this downgrade by keeping the last-applied-configuration
annotation for client-side apply updated with server-side apply.
And add a corresponding flag in kubectl (for apply), even though the
value is defaulted in kubectl with "kubectl".
The flag is required for Apply patch-type, and optional for other PATCH,
CREATE and UPDATE (in which case we fallback on the user-agent).
