Drop DataSource handling

Closes #29 (closed)

• Removes arkindex_worker.worker.MANUAL_SLUG
  • No workers affected in teklia/workers
• Removes ElementsWorker.get_ml_result_slug
  • Affects generic_exporter (here, here, here, here)
  • Affects horae_exporter (here and here)
  • Affects balsac_exporter (here, here and here)

arkindex_worker/worker/version.py

@@ -14,6 +14,13 @@ class WorkerVersionMixin(object):
 
         return worker_version
 
+    def get_worker_version_slug(self, worker_version_id: str) -> str:
+        """
+        Get worker version slug from cache if possible, otherwise make API request
+        """
+        worker_version = self.get_worker_version(worker_version_id)
+        return worker_version["worker"]["slug"]
+
     def get_ml_result_slug(self, ml_result) -> str:
         """
         Helper function to get the worker slug from element, classification or transcription.
@@ -36,5 +43,4 @@ class WorkerVersionMixin(object):
         if worker_version_id is None:
             return
 
-        worker_version = self.get_worker_version(worker_version_id)
-        return worker_version["worker"]["slug"]
+        return self.get_worker_version_slug(worker_version_id)