Replace Molecule RKE2 component placeholder assertions with real tests

User Story:

As a developer, I want real test assertions for RKE2 component so that RKE2 operator functionality is validated

Problem Statement:

RKE2 component tests don't validate cluster formation, node readiness, or kubeconfig generation - critical functionality for Kubernetes deployment.

Acceptance Criteria:

• RKE2 CRD creation validated with proper configuration
• Cluster formation tested (control plane and workers).
• Kubeconfig generation and validity verified
• Node readiness checked (kubectl get nodes)
• Network connectivity between nodes validated
• CNI plugin functionality verified
• Upgrade path testing (version changes)

Implementation Details:

Files to Modify:

• molecule/default/tasks/rke2_test.yml - Replace placeholder assertions with real tests
• molecule/default/vars/rke2_test_vars.yml - Test configurations for different cluster sizes

Dependencies:

• kubernetes Python client for cluster validation
• PyYAML for kubeconfig parsing.

Additional Notes:

Tests should validate multi-node clusters, HA configurations, and integration with other components (storage, networking). Include both single-node and multi-node scenarios.

---