Data-handling requirements for key export are under-specified

[indomitableSwan]

What are the requirements for the key server upon receipt of a key export request? For example, does the key server need to delete the data? Is this an optional parameter, or a fundamental aspect of exporting a key? What specific use cases are we attempting to meet with the "key export" feature?

To complete this ticket, the design must be adjusted to specify these requirements and clarify the relevant use case, and any corresponding implementation adjustments should be captured in key-mgmt tickets.