UI/accounts: adds a loading screen during account loading

- adds faded loading pages with a spinner animation
- starts and stops the load page during account creation and loading
- resizes the loading graphics when window is resized
- adds an event handler for DPI and scale factor changes
- removes stretching from welcome page image
- clears account creation alias box after account creation clicked

Change-Id: I5046e0bc820e91c8b2f91ca223534d93ddf916f1
Tuleap: #1010
diff --git a/WelcomePage.xaml b/WelcomePage.xaml
index f9aa112..d4f01f6 100644
--- a/WelcomePage.xaml
+++ b/WelcomePage.xaml
@@ -23,15 +23,18 @@
       xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

       mc:Ignorable="d">

 

-    <StackPanel HorizontalAlignment="Center"

-                VerticalAlignment="Center">

+    <Grid x:Name="_welcomePage_"

+        >

         <!--<TextBlock x:Uid="_welcomeMsg"

                    x:Name="_welcomeMsg_"

                    Style="{StaticResource TextStyle1}"

                    HorizontalAlignment="Center"

                    VerticalAlignment="Center"

                    TextWrapping="Wrap" />-->

-        <Image Source="Assets\TESTS\logo-ring.scale-125.png"/>

-    </StackPanel>

+        <Image x:Name="_welcomeImage_"

+            Source="Assets\TESTS\logo-ring.square-100.png"

+               Width="310"

+               Height="310"/>

+    </Grid>

 

 </Page>