webgl-debug.js should be refactored to use the WEBGL_lose_context

It would be nice to refactor https://www.khronos.org/registry/webgl/sdk/debug/webgl-debug.js to use the WEBGL_lose_context extension where it exists.

Specifically webgl-debug.js contains code to emulate context lost events and help debug them by throwing and specific times. That code though does not handle extensions in general. Using WEBGL_lose_context would solve that for implementations that support WEBGL_lose_context.

Start with webgl-debug.js at the Khronos WebGL debug SDK URL, focusing on its context-lost event emulation and handling of extensions. Compare that behavior with the WEBGL_lose_context extension and verify that supported implementations use it while the existing debugging behavior remains available where the extension is absent.

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