LibWeb: Introduce the WebGL namespace and add WebGLContextEvent

Author: https://github.com/Lubrsi
Commit: b0c2aee2e4
Pull-request: https://github.com/SerenityOS/serenity/pull/14184
Reviewed-by: https://github.com/Quaker762 ✅
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/linusg ✅
Reviewed-by: https://github.com/sunverwerth

Userland/Libraries/LibWeb/idl_files.cmake

@@ -172,6 +172,7 @@ libweb_js_wrapper(UIEvents/MouseEvent)
 libweb_js_wrapper(UIEvents/UIEvent)
 libweb_js_wrapper(URL/URL)
 libweb_js_wrapper(URL/URLSearchParams ITERABLE)
+libweb_js_wrapper(WebGL/WebGLContextEvent)
 libweb_js_wrapper(WebSockets/WebSocket)
 libweb_js_wrapper(XHR/ProgressEvent)
 libweb_js_wrapper(XHR/XMLHttpRequest)