Merge branch 'fix/requests-headers-overwritten' into 'main'

Bug fix: User headers are now prioritized over default headers

See merge request cpes/european-projects/enershare/tsg-client!79

tsg_client/controllers/RequestController.py

@@ -41,7 +41,9 @@ def request(
         if headers is None:
             headers = self.headers
         else:
-            headers.update(self.headers)
+            for key, value in self.headers.items():
+                if key not in headers:
+                    headers[key] = value
 
         if base_url is None:
             base_url = self.base_url