Generate data from Avro schemas that could be used for data validation

[Frawless]

Description

This PR adds Avro schemas for the data so the generated data could be validated against the schemas.

Type of Change

• New feature (non-breaking change which adds functionality)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit/integration tests pass locally with my changes