New: Persist sort in Select Episodes modal

Closes #7233

frontend/src/Store/Actions/episodeSelectionActions.js

@@ -24,6 +24,11 @@ export const defaultState = {
   items: []
 };
 
+export const persistState = [
+  'episodeSelection.sortKey',
+  'episodeSelection.sortDirection'
+];
+
 //
 // Actions Types
 
@@ -54,7 +59,9 @@ export const reducers = createHandleActions({
 
   [CLEAR_EPISODES]: (state) => {
     return updateSectionState(state, section, {
-      ...defaultState
+      ...defaultState,
+      sortKey: state.sortKey,
+      sortDirection: state.sortDirection
     });
   }