Remove RegisterTypes() abstract method

[duanenewman]

I think this was a result of refactoring the code into a library with support for multiple containers test frameworks. We shouldn't be calling a virtual method from a base constructor, since it can do strange things. I already had to put in check logic on the base Prism test classes to make sure it was called.. but really since it is called from the constructor it can just be done in each subclass's ctor as needed. This eliminates the need to make sure the base methods are called as well.

To Do:

• remove call to RegisterType from IoC base class ctors
• remove RegisterType from ContainerTestBase, convert all existing methods from overrides and simply call from containing class ctor.