Fundamental Changes to Self-Hosted Managed stacks should be explicitly called out when upgrading

With the introduction of rexctl, there were some architectural changes that an admin that may not have kept up with the seeming breakneck speed at which everything is currently moving. For example, an admin (me) may not have realized for hours why their instance was down because Fluxer now wants to manage its own SSL certificates instead of default allowing users to manage their own reverse proxies, and having to run a rexctl command to re-enable it.

When there are large architectural changes to the stack such as the above, actively warn the admin as part of the update script of changes that will need additional directions to be followed post-update.