Implement Argo Rollouts, NetworkPolicy, and PDB support

[bonddim]

Enhancements and new features to the base Helm chart, focusing on improved support for Argo Rollouts, as well as adding first-class support for Kubernetes NetworkPolicy and PodDisruptionBudget resources. It also refactors service template rendering and updates documentation to reflect these changes. The chart version is bumped to 0.3.0 to indicate these breaking and featureful changes.

The most important changes are:

Argo Rollouts Support and Service Handling

• Added native support for workload: rollout (Argo Rollouts), including a dedicated rollout.yaml manifest, special handling for rollout services, and automated merging of service references into rollout strategies for both canary and blue-green deployments. Additionally, the httproute.yaml template now supports canary backend weights and a dedicated rollout service.

NetworkPolicy and PodDisruptionBudget Resources

• Added support for rendering a NetworkPolicy resource when enabled, with configurable selectors, policy types, ingress, and egress rules.
• Added support for rendering a PodDisruptionBudget resource with validation for mutually exclusive minAvailable and maxUnavailable fields, as well as support for unhealthyPodEvictionPolicy.

Template and Values Refactoring

• Unified service rendering into a reusable template (_service.tpl) and updated service.yaml and new service-rollout.yaml to use this template, improving maintainability and consistency.
• Consolidated update strategy values: removed updateStrategy in favor of a single strategy field for all workload types, including rollouts.

Documentation and Versioning

• Updated documentation (README.md) to reflect new features, parameter changes, and improved descriptions for rollout, network policy, and pod disruption budget support.

Other Enhancements

• Improved HPA (hpa.yaml) to support referencing Rollout resources and to use with for resource utilization metrics, increasing flexibility.