feat: include pst_tap in enriched action topology

[marota]

Include pst_tap in Enriched Action Topology

This Pull Request updates the RecommenderService to extract and include Phase Shifter Transformer (PST) tap information in the action_topology field of enriched actions.

Changes Overview

Backend Integration (recommender_service.py)

• Updated RecommenderService._enrich_actions to extract the pst_tap attribute from the underlying action objects.
• This ensures that when PST tap variations are proposed by the recommender, the specific tap changes (e.g., {"PST1": 12}) are sent to the frontend.

Verification Results

Automated Tests

• Verified the enrichment logic with a new unit test in Expert_op4grid_recommender's test suite that specifically mocks the RecommenderService and checks for the presence of pst_tap in the output.
• Combined with the core changes in Expert_op4grid_recommender, this completes the end-to-end integration of PST actions.

Linked PR: marota/Expert_op4grid_recommender#58