Unimplemented VaultClientAPIs about plasma HOT 3 OPEN

This may be addressed by #1486 by simply deleting the unimplemented stuff.

from plasma.

There are still a few "eric, implement me" assertions, although arguably that's probably an indicator that the function isn't being used

from plasma.

Had a quick look over the remaining ones. A few that stand out to me:

• NetCliAuthVaultNodeDelete is impossible to implement with the existing network protocol, because the Cli2Auth_VaultNodeDelete message is undefined
• VaultSetNodeSeen is challenging, as described in #1246
• VaultFindOrCreateChildAgeLinkAndWait is unimplemented, unused, and blocking - that can definitely go
• The age chronicle stuff could be useful if implemented - IIRC, some age Python scripts currently do this by hand

The other ones seem to be for things that no longer exist (e. g. age czars) or are implemented elsewhere now (e. g. KI levels and CCR petitions). Those probably aren't worth restoring.

from plasma.