refactor: split KeyboardMovementObserver implementation (#1071)

## 📜 Description

Split `KeyboardMovementObserver` implementation into several files.

## 💡 Motivation and Context

The main issue is that whenever I add new lines of the code into the
file I instantly get complaints from `swiftlint` that I exceed max
allowed number of lines. I don't want to disable this rule, because I
strongly agree that fields with 300+ lines of code are hard to
read/memoize in your head.

In fact `KeyboardMovementObserver` implementation consist from 4
different (but toughly related parts):
- KVO (interactive keyboard);
- DisplayLink (to watch keyboard movement during animation)
- lifecycles methods (mount/unmount)
- listeners (subscription to keyboard events)
- animation (initialize animation driver to deliver better
synchronization when reading keyboard coordinates via `DisplayLink`)

And such structured stuff very easily can be splitted across different
files. For that I used `extension` approach and grouped logically all
parts into groups.

Now the structure of this file is more molecular and extendable, so
it'll simplify support in the future 😎

## 📢 Changelog

<!-- High level overview of important changes -->
<!-- For example: fixed status bar manipulation; added new types
declarations; -->
<!-- If your changes don't affect one of platform/language below - then
remove this platform/language -->

### iOS

- created `KeyboardMovementObserver+Listeners.swift` file
- created `KeyboardMovementObserver+Watcher.swift` file;
- created `KeyboardMovementObserver+Interactive.swift` file;
- created `KeyboardMovementObserver+Lifecycles.swift` file;
- created `KeyboardMovementObserver+Animation.swift` file;

## 🤔 How Has This Been Tested?

Tested via CI.

## 📝 Checklist

- [x] CI successfully passed
- [x] I added new mocks and corresponding unit-tests if library API was
changed

Author: kirillzyusko

ios/observers/KeyboardMovementObserver.swift

@@ -0,0 +1,21 @@
+//
+//  KeyboardMovementObserver+Animation.swift
+//  Pods
+//
+//  Created by Kiryl Ziusko on 07/08/2025.
+//
+
+extension KeyboardMovementObserver {
+  func initializeAnimation(fromValue: Double, toValue: Double) {
+    for key in ["position", "opacity"] {
+      if let keyboardAnimation = keyboardTrackingView.view?.layer.presentation()?.animation(forKey: key) {
+        if let springAnimation = keyboardAnimation as? CASpringAnimation {
+          animation = SpringAnimation(animation: springAnimation, fromValue: fromValue, toValue: toValue)
+        } else if let basicAnimation = keyboardAnimation as? CABasicAnimation {
+          animation = TimingAnimation(animation: basicAnimation, fromValue: fromValue, toValue: toValue)
+        }
+        return
+      }
+    }
+  }
+}

ios/observers/KeyboardEventsIgnorer.swift …ers/movement/KeyboardEventsIgnorer.swiftios/observers/KeyboardEventsIgnorer.swift renamed to ios/observers/movement/KeyboardEventsIgnorer.swift ios/observers/KeyboardEventsIgnorer.swift renamed to ios/observers/movement/KeyboardEventsIgnorer.swift

@@ -0,0 +1,56 @@
+//
+//  KeyboardMovementObserver+Interactive.swift
+//  Pods
+//
+//  Created by Kiryl Ziusko on 07/08/2025.
+//
+
+extension KeyboardMovementObserver {
+  func setupKVObserver() {
+    guard interactiveKeyboardObserver == nil, let view = keyboardTrackingView.view else { return }
+
+    interactiveKeyboardObserver = view.observe(\.center, options: .new) { [weak self] _, change in
+      guard let self = self, let changeValue = change.newValue else { return }
+
+      self.keyboardDidMoveInteractively(changeValue: changeValue)
+    }
+  }
+
+  func removeKVObserver() {
+    interactiveKeyboardObserver?.invalidate()
+    interactiveKeyboardObserver = nil
+  }
+
+  private func keyboardDidMoveInteractively(changeValue: CGPoint) {
+    if UIResponder.isKeyboardPreloading {
+      return
+    }
+    // if we are currently animating keyboard -> we need to ignore values from KVO
+    if !displayLink.isPaused {
+      return
+    }
+
+    let position = keyboardTrackingView.interactive(point: changeValue)
+
+    if position == KeyboardTrackingView.invalidPosition {
+      return
+    }
+
+    if position == 0 {
+      // it will be triggered before `keyboardWillDisappear` and
+      // we don't need to trigger `onInteractive` handler for that
+      // since it will be handled in `keyboardWillDisappear` function
+      return
+    }
+
+    prevKeyboardPosition = position
+
+    onEvent(
+      "onKeyboardMoveInteractive",
+      position as NSNumber,
+      position / CGFloat(keyboardHeight) as NSNumber,
+      -1,
+      tag
+    )
+  }
+}