fix(card): remove duplicate padding in card style

The Padding was applied once through the Borders Padding and once more by the ContentPresenters Margin, effectively doubling the Paddings value specified on the call-site.

Author: corvinsz

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Card.xaml

@@ -83,7 +83,6 @@
                     Background="{TemplateBinding Background}"
                     Clip="{TemplateBinding ContentClip}">
               <ContentPresenter x:Name="ContentPresenter"
-                                Margin="{TemplateBinding Padding}"
                                 HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                 VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                 Content="{TemplateBinding ContentControl.Content}"