Commented Feature: Update : [code/unity] Migrate application design to use Unity for IoC [1691]

Implement Unity and Dependency injection to enable the development of Unit Tests as Tweetinvi currently only have Integration tests.
Comments: Associated with changeset 34288: Version 0.9.0.0
- Moved User Identifier QueryParameter generation from UserQueryGenerator to in its own class
- Moved the tests of the UserQueryParameter generation into its own class