Ruffle would not polyfill a Flash embed if it had bogus attributes
in the embed tag. Now these errors are silently ignored.
Fixes the other part of #457.
Fixes part of #457. Even if the MIME type/class IDs are missing
on the embed/object tags, browsers will still attempt to play
the file as Flash if it ends in a .swf extension.
When a Ruffle player element is disconnected, attempts to play SWF files
fail semi-silently.
We also check for nested objects, since only the top should be
successful in loading.
Instead of forcing a chunk load on Webpack just so we can have Webpack prepare the WASM for us, we're now using the `no-modules` mode of `wasm-pack` manually and loading the resulting files ourselves.
I still have to force Ruffle to load outside of the extension sandbox though...