Add NIOT

[hishnash]

Add NIOTransportServices support on Apple platforms.

On apple platforms it is best to use the NIOTSEventLoopGroup and use the corresponding SSL configurations.

This PR also adds a HTTPChannelIntercepter that can be used to inspect the HTTP handshake requests (for locking etc).

[0xTim]

We can't change the tools version as we need to keep support for 5.2 - does that block the PR?

[hishnash]

I believe 5.3 is require for the

condition: .when(
                     platforms: [Platform.iOS, Platform.macOS, Platform.tvOS, Platform.watchOS]
                 )

If this is a blocker then i might look into how i could make changes to this package so that an additional package could provide the NIOTransportServices decency. (either through a subclass or a plugin like solution). what do you think would be the best approach?

[0xTim]

Add a Package@swift-5.2.swift manifest which contains the old version and then that should work (we might need to wrap the new methods in a Swift version check as well)

[hishnash]

ok i will give that a go, should i also update the GitHub workflow so that it includes both versions of swift?

[0xTim]

@gwynne could you update the CI with all the new fun stuff?

[hishnash]

@0xTim I added the checks and package file for 5.2 i think the version checks i did are also in the correct places. (i did think that this might fail if for some reason someone has a package called Network installed on linux but maybe not im not sure how the compiler works with these canImport stuff should i also but a platform condition in place?

[0xTim]

@hishnash I think canImport should be fine

[hishnash]

@0xTim cool are there any other changes i need to make.

[0xTim]

@hishnash sorry I've just spotted this! Sorry about the massive e delay. Is this now solved by #107 ?