Titlebar and Quick-Access broken when using StartScreen

[chrfin]

If you open/use the StartScreen the title bar changes text-align and the Quick-Access-Icons are gone:
Before StartScreen:

After StartScreen:

Side-Note: To even use the start-screen in the showcase you need to delete Ln 158 in TestContent.xaml as the referenced image does not exist.

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Environment

• Fluent.Ribbon v8.0.2
• Windows 10
• .NET Core 3.1

[chrfin]

I found the reason for this:

parentRibbon.TitleBar.IsCollapsed is not set back to false after the StartScreen is hidden.

I think this was introduced with the fix for #855 and the addition of var wasOpen = this.IsOpen; as IsOpen is already false there. 

We use the following workaround for now:

    StartScreen.IsOpenChanged += (s, e) => Ribbon.TitleBar.IsCollapsed = StartScreen.IsOpen;