+str #15904 Ported Tcp IO to new Stream DSL

* Port of Tcp IO to the new Stream DSL
* ~~Ordered shutdown of the server is to be discussed (was missing in the old one as well)~~
* ~~This PR also includes the broadcast fixes for #15948 which can be ignored (will be removed)~~

Fixes #15904
The disadvantage of a second parameter list is that you have to specify an extra pair of parens when creating an instance. However, since in this case users never create instances this is not really a problem.
In pattern matches the second parameter list doesn't appear at all, so this should indeed be an improvement.