Update default Razor search paths to include ~/[PagesRoot]/Shared

[DamianEdwards]

Based on feedback, I'd like to update the default Razor search paths.

We should add ~/[PagesRoot]/Shared/ to the search paths for Layouts, Partials, and Field Templates. This should be true whether searching from the context of a rendered Page or View. When searching from a Page, this path should be before ~/Views/Shared/, and when searching from a View it should be after ~/Views/Shared/.

[hishamco]

Happy to heard that, I faced this issue long time back in my Bloggy repo, when I blogged about Theming support in RazorPages