Mapping formations to surface_points_copy and orientations DataFrames

[AlexanderJuestel]

Description

This PR maps the formation according to its ID to each surface point and orientation since this information is currently not available. Further, the id_to_name function was fixed to actually take an ID from the surface points DataFrame and return the corresponding formation name. Previously, the index was taken, not the ID of the formation. A corresponding function in structural_frame.py was adapted,

Relates to #1063

Checklist

• My code uses type hinting for function and method arguments and return values.
• I have created tests which cover my code.
• The test code either 1. demonstrates at least one valuable use case (e.g. integration tests)
  or 2. verifies that outputs are as expected for given inputs (e.g. unit tests).
• New tests pass locally with my changes.

[graphite-app]

Graphite Automations

"Add gempy label" took an action on this PR • (09/30/25)

1 label was added to this PR based on Miguel de la Varga's automation.

[Leguark]

Hey Alex, thanks a lot for the PR! Adding an extra column here might look convenient, but it would come with performance and memory costs and risk duplicating data. That could lead to mismatches between IDs and formations — similar to the stability problems we had in GemPy 2.

If the goal is just to make the DataFrame look nicer in notebooks, I’d suggest adding the column dynamically in the df property using the mapping field and IDs. This approach keeps the GemPy model definition clean and unaffected.