[v20.x backport] streams: fixes for webstreams

[MattiasBuelens]

Manual backport of #51168 to v20.x. Depends on #52772, so keeping this in draft until that one lands.

This one was a bit tricky, since there are changes to transferables on v22.x that are not on v20.x (such as #50107) which also affect web streams. However, I think I made it work. 🤞