Coded UI Test - New Extensibility QFE

Introduced a new, simpler extension model for Coded UI Test, enabling the creation of plugins for custom controls (Windows Forms, WPF, ASP.NET) in minutes rather than days. This is achieved by abstracting complex processing into a proxy technology manager, exposing only a limited set of overrides via `UITechnologyElementProxy` and `UITechnologyManagerProxy` classes. This significantly reduces the effort required to customize control identification and record/playback for automation tests.