[Server]: C++-ify Prerun/postrun

[malone-at-work]

What needs to change?
Describe the server-level behavior or infrastructure that needs to be added or modified.

Additional context
Related issues, PRs, or design constraints.

[dbentley-vsql]

#254 and #551 in-progress

[dbentley-vsql]

Fixed in #551 and #563