change short_name to register_name in parameters snapshot

docs/changes/newsfragments/7012.improved

@@ -0,0 +1,2 @@
+Save the parameter snapshot under the `register_name` key in the parameters snapshot in datasets (not the station snapshot), to avoid overwritting the snapshot multiple parameters have identical `short_name`s.
+The parameter snapshot saved under the short name key is kept for backwards compatibility, but will be removed at a later time.

src/qcodes/dataset/measurements.py

@@ -673,6 +673,12 @@ def __enter__(self) -> DataSaver:
                 param.short_name: param.snapshot()
                 for param in self._registered_parameters
             }
+            parameter_snapshot.update(
+                {
+                    param.register_name: param.snapshot()
+                    for param in self._registered_parameters
+                }
+            )
             snapshot["parameters"] = parameter_snapshot
 
         self.ds.prepare(

tests/dataset/test_snapshot.py

@@ -46,6 +46,12 @@ def test_station_snapshot_during_measurement(
     snapshot_of_parameters = {
         parameter.short_name: parameter.snapshot() for parameter in (dac.ch1, dmm.v1)
     }
+    snapshot_of_parameters.update(
+        {
+            parameter.register_name: parameter.snapshot()
+            for parameter in (dac.ch1, dmm.v1)
+        }
+    )
     with measurement.run() as data_saver:
         data_saver.add_result((dac.ch1, 7), (dmm.v1, 5))