Move/Rename stuff (#11209)

-     Change namespace, and folder of FancyWindow to Content.Client.UserInterface.Controls
-     Change xaml reference from ui to controls in some places
-     Change ClientAlertsSystem from internal to public
-     Change namespace, and folder of HighDivider to Content.Client.UserInterface.Controls

Content.Client/Hands/UI/HandVirtualItemStatus.xaml

@@ -0,0 +1,3 @@
+<Control xmlns="https://spacestation14.io">
+    <Label StyleClasses="ItemStatus" Text="Blocked by" />
+</Control>