Modify RazorView to be instantiated via TypeActivator

Partial fix for #889 

This change is meant to be part of a series of changes for _ViewStart usage in host.
Do we have a bug to make an MVC typeactivator that just picks up the correct service provider? We keep repeating this code again and again. we can just make a scoped typeactivator and be done with it. It might also do some goodness for allocations.