[repository schema] Support scenario inheritance

[mkudukin]

The proposal is to add support for selective scenario inheritance as discussed in https://github.com/FIXTradingCommunity/fix-orchestra/discussions/199.

This enables a scenario to inherit the structure and attributes of another, modify the structure by adding, removing, and replacing elements, and adjust attributes while retaining a parent/child relationship, where changes to the parent entity are reflected in the child scenarios, similarly to inheritance in object-oriented design.