added transaction snackbar message

lib/domains/transaction/transaction_state.dart

@@ -20,6 +20,10 @@ final class TransactionState extends Equatable {
 
   final Transaction? currentTransaction;
 
+  final bool showSnackBar;
+  final String snackBarMessage;
+  final bool snackBarIsError;
+
   const TransactionState({
     this.globalTotal = 0,
     this.accountsTotals = const <String, double>{},
@@ -36,6 +40,9 @@ final class TransactionState extends Equatable {
     this.currentTransaction,
     this.categoryFilter,
     this.accountFilter,
+    this.showSnackBar = false,
+    this.snackBarMessage = '',
+    this.snackBarIsError = false,
   });
 
   TransactionState copyWith({
@@ -54,6 +61,9 @@ final class TransactionState extends Equatable {
     Transaction? currentTransaction,
     Category? categoryFilter,
     Account? accountFilter,
+    bool? showSnackBar,
+    String? snackBarMessage,
+    bool? snackBarIsError,
   }) {
     return TransactionState(
       globalTotal: globalTotal ?? this.globalTotal,
@@ -71,6 +81,9 @@ final class TransactionState extends Equatable {
       currentTransaction: currentTransaction ?? this.currentTransaction,
       categoryFilter: categoryFilter ?? this.categoryFilter,
       accountFilter: accountFilter ?? this.accountFilter,
+      showSnackBar: showSnackBar ?? this.showSnackBar,
+      snackBarMessage: snackBarMessage ?? this.snackBarMessage,
+      snackBarIsError: snackBarIsError ?? this.snackBarIsError,
     );
   }
 
@@ -89,6 +102,9 @@ final class TransactionState extends Equatable {
     currentTransaction,
     categoryFilter,
     accountFilter,
+    showSnackBar,
+    snackBarMessage,
+    snackBarIsError,
   ];
   
 }