feat: add LabelMatchMode field to Workload struct

[XploY04]

What this PR does / why we need it:

This PR implements the prerequisite changes in chaos-operator to support label intersection mode for precise pod targeting in chaos experiments. This is required for the litmus-go PR #777 which adds the actual intersection logic for pod selection.

Changes Made:

• Added LabelMatchMode field to ApplicationParams struct (for appinfo-based targeting)
• Added LabelMatchMode field to Workload struct (for workload-based targeting)
• Updated getTargets() function to append the label match mode (union/intersection) as a 4th parameter to the TARGETS environment variable
• Regenerated CRDs with controller-gen v0.16.5 to include the new labelMatchMode field in the OpenAPI schema
• Upgraded controller-tools from v0.9.0 to v0.16.5 for Go 1.25.1 compatibility
• Added modern Kubebuilder v3+ config structure (config/crd/bases/)

TARGETS Environment Variable Format:

TARGETS="kind:namespace:[labels]:labelMatchMode"

• labelMatchMode defaults to union (OR logic - matches ANY label)
• Can be set to intersection (AND logic - matches ALL labels)
• Fully backward compatible (defaults to union if not specified)

Example:

# For AppInfo targeting
spec:
  appinfo:
    appns: "default"
    applabel: "app=web,tier=frontend"
    appkind: "deployment"
    labelMatchMode: "intersection"  # Gets pods with app=web AND tier=frontend

# For Workloads targeting
spec:
  selectors:
    workloads:
      - kind: "deployment"
        namespace: "default"
        labels: "role=primary,cluster=prod"
        labelMatchMode: "intersection"  # Gets pods with role=primary AND cluster=prod

Which issue this PR fixes: fixes litmuschaos/litmus-go#774

Special notes for your reviewer:

• This PR is a prerequisite for litmus-go PR #777
• The chaos-runner in litmus-go will parse the 4th parameter from TARGETS env variable
• New CRDs are generated in config/crd/bases/ (modern Kubebuilder structure) while keeping deploy/crds/ for backward compatibility
• No breaking changes - all existing ChaosEngines will continue to work with default union behavior

Checklist:

• Fixes Experiments for CloudNativePG project litmus-go#774
• Labelled this PR & related issue with documentation tag
• PR messages has document related information
• Labelled this PR & related issue with breaking-changes tag - Not applicable (backward compatible)
• PR messages has breaking changes related information - Not applicable
• Labelled this PR & related issue with requires-upgrade tag - Not applicable (optional field with default)
• PR messages has upgrade related information - Not applicable
• Commit has unit tests - Covered in litmus-go PR #777
• Commit has integration tests - Will be covered in E2E tests

Related PRs:

• litmus-go: feat: add label intersection mode for precise pod targeting litmus-go#777 (implements the intersection logic using this field)