Allow updating domain and admin domain seamlessly on upgrade

[mjnagel]

Is your feature request related to a problem? Please describe.

Currently UDS Core does not (easily) support updating the domain on an existing deployment. While anywhere the domain is directly used in helm values will typically get updated, there are a number of operator-controlled-resources that need to be adjusted when the domain changes. In particular the following need to happen but do not currently:

• All virtualservices and serviceentries need to update to the new domain
• Keycloak's trusted host policy needs to be updated to the new domain
• All SSO clients need to be updated with the right domain (for redirect uris, etc)
• Related to ^ Authservice configuration must be updated with the right domain
• Potential pod cycling to ensure all the updated config is read (unsure if this is required)

Describe the solution you'd like

When I update my domain, all deployments properly read in the new domain and Pepr updates any necessary configuration so that everything works!

Describe alternatives you've considered

Document a manual process for how to shift to a new domain - this could be partially necessary with the current state of Keycloak management, but ideally we would manage this all for the end user.

Additional context

This was a TODO from #1186