Explicitly depend on NIO modules
Motivation
NIO has been split up into NIOCore, NIOPosix and NIOEmbedded. We should depend on those explicitly and not import the NIO umbrella module.
Changes
- Explicitly depend on
NIOCore,NIOPosix,NIOEmbeddedinPackage.swift - Explicitly import
NIOCore,NIOPosixandNIOEmbedded