Add an AudioPlayer component for Web projects

Add a non-visual AudioPlayer component to Web projects so applications can play audio — sound effects, narration, alarms, background tracks — from bundled project resources.

The component should load an audio resource, play, pause, and stop, report and seek within the track, expose duration, volume, and looping, and raise events when playback starts, completes, or fails. It appears on the designer shelf beside Timer rather than on the page. This would bring Web projects to parity with the desktop AudioPlayer for the common playback workflows.