* Change to GetAll to allow the usage of a nullable type in T when T is an interface.

* Change to GetAll to allow the usage of a nullable type in T when T is an interface: further change to check if val == null and if so then don't try to assign it as a property value.

* Change to Get to allow the usage of a nullable type in T when T is an interface. (effectively the same change as the previous change to GetAll.)

* Change to GetAsync and GetAllAsync to allow the usage of a nullable type in T when T is  an interface.

* Added in UserWithNullableDob and IUserWithNullableDob.

Added in tests for GetAndGetAllWithNullableValues and  GetAsyncAndGetAllAsyncWithNullableValues.

* Added in .ConfigureAwait(false) in the GetAsync Test.
Added comment to identify which issue the test relates to.

* Added NullableDates tables to the test databases.
Adjusted variable names in GetAndGetAllWithNullableValues and GetAsyncAndGetAllAsyncWithNullableValues.

* Changed IUserWithNullableDob to INullableDate.