Move Server.ContainerAttach to Daemon.ContainerAttach

This is part of an effort to break apart the legacy server package. Help wanted!

This depends on #7343, please review that first.
Also, maybe makes sense to call "logs" job, it is like attach but without hijacking for stdin. Also, with attach there can be race condition because of some output already was printed before it.
Pls add this to FIXME comment.