stream: validate writable defaultEncoding
fixes: https://github.com/nodejs/node/issues/46301
this has to be done for stream.Readable
too for consistency. I'll open another pr for readable if this gets approved
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
fixes: https://github.com/nodejs/node/issues/46301
this has to be done for stream.Readable
too for consistency. I'll open another pr for readable if this gets approved