impl endpoint for exporting courses data for surveys

Up until now, configuring self-evaluation surveys required exporting TSV files to obtain data about professors, assistants, and lecture-sharing information with manual processing for getting the subject codes.

To remove this manual step and reduce the risk of errors, this MR introduces a new API endpoint for integration with the Surveys system. This allows the required data to be retrieved automatically once the allocation process is completed.

The endpoint is publicly accessible but secured via API key authentication and is intended to be used exclusively by the Surveys system.