Add UnregisterForNotifications functor

Sources/ElixxirDAppsSDK/Functors/UnregisterForNotifications.swift

+import Bindings
+import XCTestDynamicOverlay
+
+public struct UnregisterForNotifications {
+  public var run: (Int) throws -> Void
+
+  public func callAsFunction(
+    e2eId: Int
+  ) throws {
+    try run(e2eId)
+  }
+}
+
+extension UnregisterForNotifications {
+  public static let live = UnregisterForNotifications { e2eId in
+    var error: NSError?
+    BindingsUnregisterForNotifications(e2eId, &error)
+    if let error = error {
+      throw error
+    }
+  }
+}
+
+extension UnregisterForNotifications {
+  public static let unimplemented = UnregisterForNotifications(
+    run: XCTUnimplemented("\(Self.self)")
+  )
+}
+