Add GetDefaultE2EParams functor

Sources/ElixxirDAppsSDK/GetDefaultE2EParams.swift

+import Bindings
+import XCTestDynamicOverlay
+
+public struct GetDefaultE2EParams {
+  public var run: () -> Data
+
+  public func callAsFunction() -> Data {
+    run()
+  }
+}
+
+extension GetDefaultE2EParams {
+  public static let live = GetDefaultE2EParams {
+    guard let data = BindingsGetDefaultE2EParams() else {
+      fatalError("BindingsGetDefaultE2EParams returned `nil`")
+    }
+    return data
+  }
+}
+
+extension GetDefaultE2EParams {
+  public static let unimplemented = GetDefaultE2EParams(
+    run: XCTUnimplemented("\(Self.self)")
+  )
+}