WHY
In order to fully support defining 3scale Products in OAS, we will need to leverage OpenAPI's extensions functionality to cover some Product fields that don't have a comparable analogue in native OAS.

WHAT
Design the extensions framework that the operator can use to populate Product CR fields that don't exist in native OAS. The purpose of this ticket is to both design the framework and implement the operator support to recognize and consume the extensions.

HOW
Use the kuadrantctl approach as a starting place.

DONE

• Created upstream doc defining what the OpenAPI 3scale extensions will look like
• Operator recognizes and supports OpenAPI 3scale extensions when creating Product CRs