[M5] MODE 3: Add workflow_application_id field (Kafka)

[ricardozanini]

Add workflow_application_id field to MODE 3 Kafka ingestion with CloudEvent extraction.

Implementation:

• CloudEvent mapper: Extract workflowApplicationId from CloudEvent data
• Database schema: Same as MODE 1 (shared normalized schema)
• JPA entity: Same as MODE 1 (shared entities)
• GraphQL: Same as MODE 1 (shared schema)

Acceptance Criteria:

• CloudEvent mapper extracts field
• Database column added (shared with MODE 1)
• GraphQL schema includes field and filter
• Integration test with Kafka events

Reference: ADR-0002 (Future Work: MODE 3 Implementation)

Part of: Epic kubesmarts/logic-operator#48