Feat map members containing periods

[JMolenkamp]

Alternative to #777, less impactful, keeps InvokerModel intact.
Try combining parts if no property or field was found for a single part to allow for mapping properties that contain periods.

From #777:

The InvokerModel stores the property path as a period joined string. When building the expression for a property path, this string is split on the periods, which makes it impossible to have a property name that contains periods.

Obviously, this is kinda obscure, but I actually ran into this issue. It is possible to have a property name with a period when dynamically building types where pretty much all naming restrictions go out of the window.