refactor(mobile): introduce image request registry on iOS (#27486)

* refactor: replace DispatchQueue + DispatchSemaphore with OperationQueue for image processing

* implement RequestRegistry and UnfairLock for managing cancellable requests

* implement requests registry for local and remote image processing

* remove Cancellable protocol and cancel method from request registry

* use mutex

---------

Co-authored-by: mertalev <101130780+mertalev@users.noreply.github.com>

mobile/ios/Runner/Images/ImageRequest.swift

@@ -0,0 +1,14 @@
+import Foundation
+
+struct RequestRegistry<T: AnyObject & Sendable>: ~Copyable, Sendable {
+  private let requests = Mutex<[Int64: T]>([:])
+
+  func add(requestId: Int64, request: T) {
+    requests.withLock { $0[requestId] = request }
+  }
+
+  @discardableResult
+  func remove(requestId: Int64) -> T? {
+    requests.withLock { $0.removeValue(forKey: requestId) }
+  }
+}