feat: Begins using swift argument parser and creating cli client dependency

Sources/DewPointController/SharedOptions.swift

@@ -0,0 +1,50 @@
+import ArgumentParser
+import CliClient
+import Logging
+import Models
+import MQTTNIO
+
+extension Application {
+
+  struct SharedOptions: ParsableArguments {
+    @Option(
+      name: [.short, .customLong("env-file")],
+      help: "A file path to an env file."
+    )
+    var envFile: String?
+
+    @Option(
+      name: [.short, .customLong("log-level")],
+      help: "Set the logging level."
+    )
+    var logLevel: LogLevelContainer?
+
+    @Option(
+      name: [.short, .long],
+      help: "Set the MQTT connecition version."
+    )
+    var version: String?
+
+    func envVarsRequest(logger: Logger?) -> CliClient.EnvVarsRequest {
+      .init(envFilePath: envFile, logger: logger, version: version)
+    }
+
+  }
+}
+
+/// A container type for making `Logger.Level` into a type
+/// that can be parsed as a command line argument.  This is
+/// to suppress warnings vs. having `Logger.Level` adopt the
+/// protocol.
+@_spi(Internal)
+public struct LogLevelContainer: ExpressibleByArgument {
+  public let logLevel: Logger.Level?
+
+  public init?(argument: String) {
+    self.logLevel = .init(rawValue: argument.lowercased())
+  }
+
+  public func callAsFunction() -> Logger.Level? {
+    logLevel
+  }
+}