[CSS] Including a StyleSheet throws an error on reload

[davidortinau]

Including a CSS file works on the initial run.

Global.css (EmbeddedResource):

.superLabel {
    color: black;
    background-color: transparent;
    font-size: 64;
}

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:XAMLator.SampleApp"
             x:Class="XAMLator.SampleApp.MainPage">
    
    <ContentPage.Resources>
        <StyleSheet Source="/Global.css"/>
    </ContentPage.Resources>
    
    <StackLayout>
        <!-- Place new controls here -->
        <Label Text="This is my page!"
           TextColor="White"    
           HorizontalOptions="Center"
           BackgroundColor = "Red"
           class="superLabel"
           VerticalOptions="CenterAndExpand" />
    </StackLayout>
</ContentPage>

However upon hitting save and triggering a reload, XAMLator throws an eval error.

[ylatuya]

Fixed in #10