Update delegates to use agile support from IObjectReference

[manodasanW]

Delegates have their own logic today to make them agile. They can be updated to make use of the one that is now built into IObjectReference instead and not have to do custom logic. But given the delegates logic are in the projection it means we need to be able to guarantee that WinRT.Runtime has the changes that make it agile which we can only guarantee on the next assembly version increase.

We should also add actual non agile delegate tests as the current ones are considered agile even though they don't implement IAgileObject because they implement the free threaded marshaler.

See #844

[manodasanW]

Changes staged in https://github.com/microsoft/CsWinRT/tree/manodasanw/delegateagile

[manodasanW]

Note assembly version change was done in CsWinRT 1.3.0