iOS Text Input Refactoring (#3004)

iOS text input had a single monolithic `UIKitTextInputService` that
handled both the Compose path (Compose draws caret/selection) and the
NITI path (UIKit owns caret, handles and context menu) with `if
(usingNativeTextInput)` branches throughout, and a single shared view
reused across sessions.

Each text input session now gets its own dedicated connection object
that owns its view for the duration of the session. The two paths are
split into separate classes with no branching in shared code.

Class Hierarchy changes

**Before:**
```
UIKitTextInputService
└── IntermediateTextInputUIView (IOSSkikoInput protocol)
```

**After:**
```
UIKitTextInputService
├── ComposeTextInputConnection (TextInputConnection) → ComposeTextInputView (TextEditingDelegate)
└── NativeTextInputConnection  (TextInputConnection) → NativeTextInputView  (NativeTextEditingDelegate)
```

`SelectionContainerConnection` extends `ComposeTextInputConnection` and
makes the SelectionContainer menu scenario explicit — instead of
scattered conditions inside `showMenu`, there is now a dedicated
connection type that clearly represents opening a context menu without
an active text input session.

### Fixes:
[CMP-9972](https://youtrack.jetbrains.com/issue/CMP-9972) [iOS] Refactor
iOS Text Input

## Testing
This should be tested by QA

## Release Notes
N/A

Author: mazunin-v-jb

compose/ui/ui-uikit/src/iosMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPEditMenuView.h

@@ -16,12 +16,10 @@
 
 #import <UIKit/UIKit.h>
 #import "CMPEditMenuCustomAction.h"
-#import "CMPTextInputView.h"
 
-@interface CMPEditMenuView : CMPTextInputView
+@interface CMPEditMenuView : UIView
 
 @property (readonly) BOOL isEditMenuShown;
-@property (readonly) BOOL shouldUseNonComposeMenuActions;
 
 - (void)showEditMenuAtRect:(CGRect)targetRect
                       copy:(void (^)(void))copyBlock
@@ -44,8 +42,4 @@
 
 - (UIView *)inputAccessoryView;
 
-- (void)activateTextInputInteractionIfNeeded;
-
-- (void)deactivateTextInputInteractionIfNeeded;
-
 @end

compose/ui/ui-uikit/src/iosMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPEditMenuView.m

@@ -74,7 +74,6 @@ @interface CMPEditMenuView() <UIEditMenuInteractionDelegate>
 
 @property (assign, nonatomic) CGRect targetRect;
 @property (assign, nonatomic) BOOL isEditMenuShown;
-@property (assign, nonatomic) BOOL shouldUseNonComposeMenuActions;
 
 @property (readwrite) UIEditMenuInteraction* editInteraction API_AVAILABLE(ios(16.0));
 
@@ -325,9 +324,7 @@ - (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
     if (@selector(customAction8:) == action) return self.customActions.count > 8;
     if (@selector(customAction9:) == action) return self.customActions.count > 9;
 
-    if (self.shouldUseNonComposeMenuActions) {
-        return [super canPerformAction:action withSender:sender];
-    } else { return NO; }
+    return NO;
 }
 
 - (void)copy:(id)sender {
@@ -441,24 +438,4 @@ - (UIMenu *)editMenuInteraction:(UIEditMenuInteraction *)interaction
     return [UIMenu menuWithTitle:@"" children:allActions];
 }
 
-- (void)activateTextInputInteractionIfNeeded {
-    if (@available(iOS 17, *)) {
-        for (id<UIInteraction> interaction in self.interactions) {
-            if ([interaction isKindOfClass:[UITextSelectionDisplayInteraction class]]) {
-                [((UITextSelectionDisplayInteraction *)interaction) setActivated:YES];
-            }
-        }
-    }
-}
-
-- (void)deactivateTextInputInteractionIfNeeded {
-    if (@available(iOS 17, *)) {
-        for (id<UIInteraction> interaction in self.interactions) {
-            if ([interaction isKindOfClass:[UITextSelectionDisplayInteraction class]]) {
-                [((UITextSelectionDisplayInteraction *)interaction) setActivated:NO];
-            }
-        }
-    }
-}
-
 @end

compose/ui/ui-uikit/src/iosMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPTextInputView.h

@@ -26,4 +26,8 @@ NS_ASSUME_NONNULL_BEGIN
                                                 atCharacterOffset:(NSInteger)offset CMP_ABSTRACT_FUNCTION;
 NS_ASSUME_NONNULL_END
 
+- (void)activateTextInputInteractionIfNeeded;
+
+- (void)deactivateTextInputInteractionIfNeeded;
+
 @end

compose/ui/ui-uikit/src/iosMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPTextInputView.m

@@ -125,4 +125,24 @@ - (void)insertText:(nonnull NSString *)text {
     CMP_ABSTRACT_FUNCTION_CALLED
 }
 
+- (void)activateTextInputInteractionIfNeeded {
+    if (@available(iOS 17, *)) {
+        for (id<UIInteraction> interaction in self.interactions) {
+            if ([interaction isKindOfClass:[UITextSelectionDisplayInteraction class]]) {
+                [((UITextSelectionDisplayInteraction *)interaction) setActivated:YES];
+            }
+        }
+    }
+}
+
+- (void)deactivateTextInputInteractionIfNeeded {
+    if (@available(iOS 17, *)) {
+        for (id<UIInteraction> interaction in self.interactions) {
+            if ([interaction isKindOfClass:[UITextSelectionDisplayInteraction class]]) {
+                [((UITextSelectionDisplayInteraction *)interaction) setActivated:NO];
+            }
+        }
+    }
+}
+
 @end