Need to fully implement object to VARIANT.

[JeremyKuhne]

I've added a FromObject method on VARIANT that only handles null and string. It needs to handle the flip side to ToObject in order to stop using Marshal for conversion. (Necessary for enabling trimming and AOT scenarios where runtime COM interop is disabled.)

[JeremyKuhne]

The difficult part of this will be what to do with reference types. Needs some investigation of how things get turned into VT_DISPATCH or VT_UNKNOWN in the runtime.