Using COM Wrappers makes the library trim compatible.

* Use function pointers instead of delegates
* Rename Guid to IID
* Better interop to closely match the native side
* Release any COM pointer that was QueryInterface
* Use pointers instead of Marshal.PtrToStructure/StructureToPtr

* No need for a VTable struct, just set each function pointer right into the table
* Wrap all managed calls in try-catch and return HResult

* Rename methods
* Use COM naming
* Fix method signature to use pointer instead of out.
* CheckStatus => ThrowExceptionForHR

* Pass -1 to Marshal.GetExceptionForHR so it doesn't query GetErrorInfo, and always returns the correct exception type
* Create the PictureWrapper with UniqueInstance, so it doesn't get cached. Caching it causes lifetime issues.