Add Roslyn Analyzers for LINQ DSL

[Athari]

1. Check arguments of all constructors and methods that accept object and params object[] as an argument and check values only at runtime. Check block-inline hierarchy, check elements that can't have children etc.

2. Suggesting to always set Color and BackgroundColor on Document may also be a good idea.

3. Avoid use of LineWidth.Heavy (limited font support). Check that combinations on line widths in LineChar are valid (heavy and double can't be combined).

4. Double assignment of the same attached property (the last assignment wins).

If Roslyn can access XAML, check element hierarchy there too.