feat: cipherstash-proxy helm chart

[calvinbrewer]

Adds a helm chart for deploying Proxy to a K8s cluster:

• Proxy deployment with resource requests/limits and preconfigured liveliness and readiness probes on TPC port 6432
• Service definition for the Proxy ingress
• Service definition for the P8s metrics collection with preconfigured labels to be ingested by OTEL/P8s
• Horizontal Pod Autoscaler configured to keep the resource consumption around 80% average
• Secret management / static definitions for database and CipherStash creds to support both on prod and dev

Acknowledgment

By submitting this pull request, I confirm that CipherStash can use, modify, copy, and redistribute this contribution, under the terms of CipherStash's choice.

[tobyhede]

Couple of comments, but LGTM

[tobyhede]

Is it worth adding some of the logging options here?

Important ones would be:

CS_LOG__FORMAT
CS_LOG__LEVEL

If it works like docker-compose.yml the env options need to be explicitly declared or they are not passed through.

[tobyhede]

There are some TLS config settings too that might be worth adding

[calvinbrewer]

@tobyhede All your points are valid I've created follow up action items to address them