0.4.20 - Nuget Release

Fixed Connection Creation "Hang" behavior that could occur when trying to create a Dataverse Service Client inside a thread.
Fixed an issue with ILogger not propagating correctly when used with connection string flows.
Fixed an issue when attempting to Null a lookup that would cause a Microsoft.OData.ODataException: Does not support untyped value in non-open type error
Changed the behavior of Update message to be consistent with Organization Service Update behavior instead of an Upsert behavior.
Added compensating code to deal with a null ref issue when logging which could cause a client crash.