Coded UI Test Extensibility V2

This post details the V2 extensibility changes for Coded UI Tests, focusing on windowless control support (including Modern Apps), control-specific targeting, and APIs not tied to window handles. Key design changes include modifications to authoring logic, where the Technology Abstraction Layer (TAL) stitches query IDs based on UIA hierarchy and queries registered plugins. Playback/Navigation now uses AutomationElement as a common factor for technology switches. New APIs in UITechnologyManagerProxy/UITechnologyManager and UITechnologyElementProxy/UITechnologyElement are introduced to facilitate these changes, with default implementations for backward compatibility.