To support this, we first must use an async entrypoint to the CLI, which
we do by changing the lint and analyze commands to conform to
`AsyncParsableCommand`.
The in order to map over the closures with suspension points, we pull in
CollectionConcurrencyKit as a new dependency.
This change does not touch SwiftLintFramework, only the CLI target.
* Integrate OS Signposts to help profile SwiftLint performance
* Split LintOrAnalyzeCommand.lintOrAnalyze(_:) into two functions
Using a builder reference type to share common mutable state.
Martin Redington