Added playing song info view and view model.

Harmonia.UI/Views/PlayingSongInfo.axaml

@@ -0,0 +1,27 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:vm="clr-namespace:Harmonia.UI.ViewModels"
+			 xmlns:converter="clr-namespace:Harmonia.UI.Converters"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+			 DataContext="{x:Static vm:ViewModelLocator.PlayingSongInfoViewModel}"
+             x:Class="Harmonia.UI.Views.PlayingSongInfo"
+             x:DataType="vm:PlayingSongInfoViewModel">
+	<Grid>
+		<Image Source="{Binding SongImageSource, Mode=OneWay}" Stretch="UniformToFill" HorizontalAlignment="Center" VerticalAlignment="Center">
+			<Image.Effect>
+				<BlurEffect Radius="20" />
+			</Image.Effect>
+			<Image.RenderTransform>
+				<ScaleTransform ScaleX="1.05" ScaleY="1.05" />
+			</Image.RenderTransform>
+		</Image>
+		<Canvas Background="#99000000"></Canvas>
+		<Image Source="{Binding SongImageSource}" Stretch="Uniform" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="20">
+			<Image.Effect>
+				<DropShadowEffect BlurRadius="10" Opacity=".4" OffsetX="3" OffsetY="3" />
+			</Image.Effect>
+		</Image>
+	</Grid>
+</UserControl>