Fixes

• Fixes [Bug] Many "search using" sources are showing non CC-licensed results #228 by @zackkrida

Description

This pull request addresses the issue where certain sources on the Creative Commons search platform were not correctly filtering results based on CC licenses. Users might have inadvertently accessed non-CC licensed works due to this issue.

The sources affected include:

• Soundcloud, Wikimedia Commons, and Google Images – where filtering for CC-licensed content was not applied correctly.
• ccMixter – which was entirely broken and did not return any results.

The fix ensures that all these sources now return only CC-licensed content, or function properly in the case of ccMixter.

Technical details

• The URL structures for the affected sources were updated to apply the correct CC license filtering.
• Adjustments were made to the API integration to ensure proper data retrieval from each source.

Tests

1. Verified that Soundcloud, Wikimedia Commons, and Google Images now correctly filter results to only show CC-licensed works.
2. Tested ccMixter to confirm it returns results as expected.
3. Ensured that other unaffected sources continue to function correctly.

Screenshots

Checklist

• My pull request has a descriptive title.
• My pull request targets the default branch of the repository (main or master).
• My commit messages follow [best practices][best_practices].
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made.
• I added or updated documentation (if applicable).
• I verified the project locally and ensured there are no visible errors.