Add back button to create report view; fix change title not warning about unsaved

src/MayShow.Shared/Views/CreatePDFReportView.axaml

@@ -15,6 +15,13 @@
   </UserControl.Resources>
   <Grid ColumnDefinitions="*"
         RowDefinitions="Auto, 2*, Auto, Auto, *">
+    <Button Command="{Binding ReturnToMainMenu}"
+            Grid.Row="0"
+            HorizontalAlignment="Left"
+            VerticalAlignment="Top"
+            Margin="4,4,0,4">
+        <TextBlock><Run Text="&#xf060;" FontFamily="{StaticResource FontAwesomeSolid}"/> Return to Main Menu</TextBlock>
+    </Button>
     <StackPanel Orientation="Vertical"
                 Spacing="2"
                 Margin="0,4,0,0">

src/MayShow.Shared/Views/ShutdownCheckView.axaml

@@ -18,7 +18,7 @@
                    FontWeight="Bold"
                    TextWrapping="Wrap"
                    FontSize="14"
-                   Text="Do you want to save your data before the program is closed?"/>
+                   Text="Do you want to save your data before closing?"/>
         <StackPanel Orientation="Horizontal"
                     Spacing="8">
             <Button Command="{Binding SaveAndShutdown}"
@@ -31,7 +31,7 @@
                     HorizontalAlignment="Right"
                     Margin="0,4,0,4"/>
             <Button Command="{Binding CancelShutdown}"
-                    Content="Cancel Program Shutdown"
+                    Content="Cancel"
                     HorizontalAlignment="Right"
                     Margin="0,4,0,4"/>
         </StackPanel>