Auto merge of #24687 - ferjm:mediaelementaudionode, r=Manishearth

WebAudio MediaElementAudioSourceNode implementation

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #22370
- [X] There are tests for these changes

Depends on https://github.com/servo/media/pull/321

Tested with https://ferjm.github.io/webaudio-examples/media-source-buffer/

I am still investigating why it is playing back with a low rate.

tests/wpt/mozilla/meta/MANIFEST.json

@@ -19023,7 +19023,7 @@
    "testharness"
   ],
   "mozilla/interfaces.html": [
-   "3578a6e01cc3bb6daf8b4942d672ecb7da1ff6b5",
+   "4006cae2d79ba4ca21c229084fcb528b8a4156f1",
    "testharness"
   ],
   "mozilla/interfaces.js": [

tests/wpt/mozilla/tests/mozilla/interfaces.html

@@ -163,6 +163,7 @@ test_interfaces([
   "InputEvent",
   "KeyboardEvent",
   "Location",
+  "MediaElementAudioSourceNode",
   "MediaError",
   "MediaList",
   "MediaQueryList",