feat(util): add ResourceList for batch resource operations

Add a utility class that provides fabric8-style batch operations on
multiple Kubernetes resources. Features include:
- fromStream()/fromYaml() for loading from YAML
- from() factory methods for programmatic creation
- Batch create(), delete(), serverSideApply() operations
- inNamespace() to override resource namespaces
- continueOnError() for fault-tolerant batch processing
- Immutable resource list with getResources()

Also adds comprehensive unit tests covering resource loading,
factory methods, and chaining operations.

Author: brendandburns