ActivationsExtractorHelper signature change

[PR #492 ](https://github.com/brain-score/vision/pull/492) adds a `ActivationsExtractorHelper.set_visual_degrees()` method to the `ActivationsExtractorHelper`. The `ModelCommitment` base class calls its `_extractor.set_visual_degrees()`, which should be protected. A nicer engineering solution would be to change the signature of `ActivationsExtractorHelper`, which would require changing all model wrappers.

This issue is left here to keep note of the change on the request of @mschrimpf.

Start by reviewing PR #492 and the ActivationsExtractorHelper and ModelCommitment classes to understand the current set_visual_degrees() flow. Locate all model wrappers that implement or consume the helper, then determine the complete signature change and update scope. Done means the new interface is consistent across the wrappers and the protected behavior described in the issue is preserved.

Written by the indexing model from the issue text.