HParams: Make experiment name column sortable and movable (#6473)

## Motivation for features / changes
The experiment name column should always have been movable and sortable
but it was created before those properties existed and didn't get
updated until now.

Author: rileyajones

tensorboard/webapp/runs/store/runs_reducers.ts

@@ -355,6 +355,8 @@ const {initialState: uiInitialState, reducers: uiNamespaceContextedReducers} =
               name: 'experimentName',
               displayName: 'Experiment',
               enabled: true,
+              movable: true,
+              sortable: true,
             },
           ];