[SG-497] Prevent registering health check on self hosted

[gbubemismith]

Type of change

- [ ] Bug fix
- [ ] New feature development
- [X] Tech debt (refactoring, code cleanup, dependency upgrades, etc)
- [ ] Build/deploy pipeline (DevOps)
- [ ] Other

Objective

Due to ongoing discussions, it would make sense not to allow the health check endpoint on self-hosted.

Code changes

I've updated the health checks to not register when the application is self-hosted. Additionally, I replaced the usage of string.IsNullOrEmpty with CoreHelpers.SettingHasValue for a more reliable way to check if a setting has been provided.

Before you submit

• Please check for formatting errors (dotnet format --verify-no-changes) (required)
• If making database changes - make sure you also update Entity Framework queries and/or migrations
• Please add unit tests where it makes sense to do so (encouraged but not required)
• If this change requires a documentation update - notify the documentation team
• If this change has particular deployment requirements - notify the DevOps team

[justindbaur]

I think this is the formatting issue you're getting but otherwise looks good to me.

[withinfocus]

Appreciate this! Solid result for all our customers.