Define a backup and restore process for Solution Server

[jwmatthews]

As an Administrator, I want a reliable means of backing up and restoring the data in the Solution Server.

Ideas to consider:

• Document manual commands to preserve configuration and backup/restore postgres data
• Document usage of Velero to run periodic/on-demand backups of the Solution Server configuration & database

Note that the Hub has this utility to help with export/import of Hub data:

• https://github.com/konveyor/tackle2-hub/tree/main/hack/tool