Add publisher interfaces for changes to workflow definitions, task definitions and schedules.

Need to capture changes to defined workflows, task definitions, and schedules. A simple interface similar to WorkflowStatusListener

### Alternatives

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### Additional context

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Start by reading the existing WorkflowStatusListener interface and tracing where workflow definitions, task definitions, and schedules are changed. Determine the publisher interface shape and the change events each resource needs; the work is done when all three change types can be captured through clearly defined interfaces.

Written by the indexing model from the issue text.