clear toast on tap

this adds a generator showDismissibleSnackBar which by default allows
tapping to clear snack bar toasts. all SnackBar properties are still
available and the

all callers should now use showDismissibleSnackBar() instead of calling
ScaffoldMessenger.of(context).showSnackBar(SnackBar())

lib/helpers/snack_bar_builder.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+
+// showDismissibleSnackBar shows  a [SnackBar] with tap to dismiss
+// all other properties are default and optional
+void showDismissibleSnackBar(
+  BuildContext context, {
+  Key? key,
+  required Widget content,
+  Color? backgroundColor,
+  double? elevation,
+  EdgeInsetsGeometry? margin,
+  EdgeInsetsGeometry? padding,
+  double? width,
+  ShapeBorder? shape,
+  HitTestBehavior? hitTestBehavior,
+  SnackBarBehavior? behavior,
+  SnackBarAction? action,
+  double? actionOverflowThreshold,
+  bool? showCloseIcon,
+  Color? closeIconColor,
+  Duration? duration,
+  bool? persist,
+  Animation<double>? animation,
+  void Function()? onVisible,
+  DismissDirection? dismissDirection,
+  Clip? clipBehavior,
+}) {
+  final messenger = ScaffoldMessenger.of(context);
+  messenger.showSnackBar(
+    SnackBar(
+      key: key,
+      content: GestureDetector(
+        onTap: () => messenger.hideCurrentSnackBar(),
+        child: content,
+      ),
+      backgroundColor: backgroundColor,
+      elevation: elevation,
+      margin: margin,
+      padding: padding,
+      width: width,
+      shape: shape,
+      hitTestBehavior: hitTestBehavior,
+      behavior: behavior,
+      action: action,
+      actionOverflowThreshold: actionOverflowThreshold,
+      showCloseIcon: showCloseIcon,
+      closeIconColor: closeIconColor,
+      duration: duration ?? const Duration(seconds: 4),
+      persist: persist,
+      animation: animation,
+      onVisible: onVisible,
+      dismissDirection: dismissDirection ?? DismissDirection.down,
+      clipBehavior: clipBehavior ?? Clip.hardEdge,
+    ),
+  );
+}