Issues with `Implemented by Inaccessible`

[PascalSenn]

Problem:
The algorithm for ensuring interface validity in the composite schema has multiple issues:

1. The algorithm references execution schema concepts (e.g., @inaccessible) that are not applicable to the composite schema.
2. The logic assumes that some types/fields are not visible in the merged (composite) schema, which contradicts the nature of the composite schema where everything is visible.
3. The current rule does not correctly handle cases where interfaces implement other interfaces, requiring the implementation of all fields.

Proposed Solution:

• Update the algorithm to align with the composite schema context, removing references to execution schema-specific elements like @inaccessible.
• Ensure that the rule validates interface implementation correctly for interfaces that implement other interfaces