LibWeb/WebAudio: Implement control message queue

[Prospero23]

Revives #5535 and splits it into two commits with fixes for changes requested by @gmta.

Message of original PR:

Summary

Implements the WebAudio control message queue as specified in the Web Audio API

Changes

-Added ControlMessageQueue class with thread-safe operations
-Integrated queue into BaseAudioContext
-Updated AudioContext methods (suspend/resume/close) to use the queue
-Updated AudioScheduledSourceNode to queue start/stop messages

Testing

• Added custom integration test for the control message queue

[Prospero23]

I am not sure if WEB_PLATFORM_OBJECT and GC_DECLARE_ALLOCATOR should be on the queue but they were on the original PR so I left them.

Should something that is not declared to JS still be a WEB_PLATFORM_OBJECT? Almost certainly just confusion caused by lack of understanding on my part.