Fixes a number of cross platform build issues:

- Managed tools which run as a part of build are now prefixed with
`mono ` in a standardized fashion.  This is now uniformly applied to
all tools for generating bound trees, syntax nodes, etc …
- Remove WPF references from TestUtiliites.csproj.
- Used reflection to access the GetRuntimeInterfaceAsObject API as it
is unavailable in the Mono APIs.