Add LogsListener

Sources/ElixxirDAppsSDK/LogsListener.swift

+import Bindings
+
+public struct LogsListener {
+  public var listen: (@escaping (String) -> Void) -> Void
+
+  public func callAsFunction(callback: @escaping (String) -> Void) {
+    listen(callback)
+  }
+}
+
+extension LogsListener {
+  public static func live() -> LogsListener {
+    LogsListener { callback in
+      let listener = Listener(onLog: callback)
+      BindingsRegisterLogWriter(listener)
+    }
+  }
+}
+
+private final class Listener: NSObject, BindingsLogWriterProtocol {
+  init(onLog: @escaping (String) -> Void) {
+    self.onLog = onLog
+    super.init()
+  }
+
+  let onLog: (String) -> Void
+
+  func log(_ p0: String?) {
+    guard let p0 = p0 else {
+      fatalError("BindingsLogWriter.log received `nil`")
+    }
+    onLog(p0)
+  }
+}
+
+#if DEBUG
+extension LogsListener {
+  public static let failing = LogsListener { _ in
+    fatalError("Not implemented")
+  }
+}
+#endif