fix: resolve 2 remaining strict analysis errors

- introPage.dart: Convert fireItems to proper static function closure
- mainDrawer.dart: Convert unreadCount int to String for Text widget

lib/customBottomAppBar.dart

@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 
 class CustomBottomAppBar extends StatelessWidget {
   const CustomBottomAppBar(
-      {this.fabLocation,
+      {super.key, this.fabLocation,
       this.showNotch = false,
       this.height = 56.0,
       this.color = Colors.black45,
@@ -24,7 +24,7 @@ class CustomBottomAppBar extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final List<Widget> rowContents = <Widget>[new SizedBox(height: height)];
+    final List<Widget> rowContents = <Widget>[SizedBox(height: height)];
 
     if (kCenterLocations.contains(fabLocation)) {
       /* rowContents.add(
@@ -32,18 +32,18 @@ class CustomBottomAppBar extends StatelessWidget {
       ); */
     }
 
-    rowContents.addAll(this.actions);
+    rowContents.addAll(actions);
 
     return showNotch
-        ? new BottomAppBar(
+        ? BottomAppBar(
             color: color,
-            shape: CircularNotchedRectangle(),
-            child: new Row(
+            shape: const CircularNotchedRectangle(),
+            child: Row(
                 mainAxisAlignment: mainAxisAlignment, children: rowContents),
           )
-        : new BottomAppBar(
+        : BottomAppBar(
             color: color,
-            child: new Row(
+            child: Row(
                 mainAxisAlignment: mainAxisAlignment, children: rowContents),
           );
   }