Implement Service Binding Mechanism

[jcoresongres]

Feature request

Supabase could implement Kubernetes' Service Binding mechanism (https://servicebinding.io/) to avoid having to explicitly add the credentials to Supabase configuration, and instead having Kubernetes inject them, materializing inside of Supabase's container as files with a specific structure and path. Service Binding is harmless on non-K8s environments (Supabase only needs to add some trivial code to detect if configuration files with Service Binding conventions exist, and if so reading them). This would enhance the UX as no credentials need to be hardcoded anywhere nor stored in vaults.