[namespace-registry] add new namespace "vco"

[c-suh]

Namespace ID Requested: vco

Associated Namespace Details: NASA-PDS/operations#426

NOTE: for the PR, please use this issue number and not the operations issue number

[c-suh]

@jshughes apologies I was hasty in creating this ticket and need clarification from Jordan about whether this is an actual task. I will close this for now and reopen it if needed.