Revert "filtered_*: initially empty list"

This reverts commit 84d2355.

Author: dawidd6

lib/blocs/filtered_casks/filtered_casks_bloc.dart

@@ -16,7 +16,9 @@ class FilteredCasksBloc extends Bloc<FilteredCasksEvent, FilteredCasksState> {
   FilteredCasksBloc({required this.bloc})
       : super(FilteredCasksState(
           filter: RegExp(''),
-          casks: [],
+          casks: bloc.state is CasksLoadedState
+              ? (bloc.state as CasksLoadedState).casks
+              : [],
         )) {
     _subscription = bloc.stream.listen((state) {
       if (state is CasksLoadedState) {

lib/blocs/filtered_formulae/filtered_formulae_bloc.dart

@@ -17,7 +17,9 @@ class FilteredFormulaeBloc
   FilteredFormulaeBloc({required this.bloc})
       : super(FilteredFormulaeState(
           filter: RegExp(''),
-          formulae: [],
+          formulae: bloc.state is FormulaeLoadedState
+              ? (bloc.state as FormulaeLoadedState).formulae
+              : [],
         )) {
     _subscription = bloc.stream.listen((state) {
       if (state is FormulaeLoadedState) {