Adding k8s labels

[ayeshakhan2004]

Description

This PR standardizes Kubernetes recommended labels across the openhands and runtime-api charts. It introduces a central _helpers.tpl for the main chart and ensures all resources including Deployments, Services, and CronJobs carry the proper app.kubernetes.io/component and part-of metadata.

**Fixes #497 **

Helm Chart Checklist

• I have updated the version field in Chart.yaml for each modified chart
• I have tested the chart upgrade path from the previous version
• I have verified backwards compatibility with existing values.yaml configurations
• I have updated the chart's README.md if there are any breaking changes or new required values

Additional Notes

• Created _helpers.tpl for the openhands chart to support openhands.labels and openhands.selectorLabels.
• Updated 3 Deployments (server, integrations, mcp) and all related CronJobs with consistent component labels.
• Patched missing metadata and pod template labels in the runtime-api CronJobs (cleanup, db-cleanup, etc.).
• Standardized labels to improve resource discovery and support bundle log collection.