Add GetDefaultCmixParams functor

Sources/ElixxirDAppsSDK/GetDefaultCmixParams.swift

+import Bindings
+import XCTestDynamicOverlay
+
+public struct GetDefaultCmixParams {
+  public var run: () -> Data
+
+  public func callAsFunction() -> Data {
+    run()
+  }
+}
+
+extension GetDefaultCmixParams {
+  public static let live = GetDefaultCmixParams {
+    guard let data = BindingsGetDefaultCMixParams() else {
+      fatalError("BindingsGetDefaultCMixParams returned `nil`")
+    }
+    return data
+  }
+}
+
+extension GetDefaultCmixParams {
+  public static let unimplemented = GetDefaultCmixParams(
+    run: XCTUnimplemented("\(Self.self)")
+  )
+}