soroban-rpc: Production-ready helm-chart

[paulbellamy]

What problem does your feature solve?

Easy way for infra providers (and ourselves) to run soroban-rpc (if they're already on k8s).

What would you like to see?

We should take the manifests from https://github.com/stellar/kube/pull/1337, and the image from #382, and combine them into a production-ready helm-chart for deploying soroban-rpc.

It should include:

• Healthchecks and automatic restarts
• Example docs for upgrading to a new version
• Persistent volumes for data, as needed
• Make sure to test upgrades when using persistent volumes

What alternatives are there?

[paulbellamy]

We should probably also use a k8s ConfigMap for the config instead of having the config on a persistent volume.

[2opremio]

For the record, there is an existing helm chart at https://github.com/stellar/helm-charts/tree/main/charts/soroban-rpc

[sreuland]

Ops is working in tandem on this aspect, and in process of refactoring the existing helm chart to latest rpc runtime, with review up - stellar/helm-charts#53