Replaces all the foundation imports.
One issue is that `HTTPClient.init?(httpsURLWithSocketPath socketPath:
String, uri: String = "/")` uses `addingPercentEncoding()` from
Foundation. So instead, we use a pure Swift impl. that does the same.
We also need to disable default traits from `swift-configuration` to
prevent linking Foundation, because the `JSON` trait does that.
This also adds a linkage test to prevent regressions to CI.
Swift log now has an InMemoryLogHandler. Lets depend on that instead of
having our own `CollectEverythingLogHandler`.
I've added an extension on top, to make it easier to create the logger
too
Result: less code
Migrate CI to use GitHub Actions.
### Motivation:
To migrate to GitHub actions and centralised infrastructure.
### Modifications:
Changes of note:
* Adopt swift-format using rules from SwiftNIO.
* Remove scripts and docker files which are no longer needed.
* Disabled warnings-as-errors on Swift 6.0 CI pipelines for now.
### Result:
Feature parity with old CI.
Mads Odgaard
hamzahrmalik
Konrad `ktoso` Malawski
Rick Newton-Rogers
David Nadoba