Add `web.media` externals

[dosier]

Hey, I am building a multiplatform library for audio processing.

For my JS target I could simply depend upon org.jetbrains.kotlin-wrappers:kotlin-browser-js, but for WamJS targets I read in the docs that I should use this library.

The issue I am having is that the web api functionality I need is not present in this library, namely components under the web.media package. My current solution is to provide the externals myself but it would be nice if they were present in this library.