[Cocoa] Enable vertical writing mode for form controls

https://bugs.webkit.org/show_bug.cgi?id=264692
rdar://118283277

Reviewed by Tim Nguyen.

Enable support for the `vertical-lr` and `vertical-rl` `writing-mode` values
on `<button>`, `<textarea>`, `<progress>`, `<meter>`, `<input>`, and `<select>`
elements.

* Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml:

Canonical link: https://commits.webkit.org/270647@main

Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml

@@ -7051,16 +7051,19 @@ VerifyWindowOpenUserGestureFromUIProcess:
 
 VerticalFormControlsEnabled:
   type: bool
-  status: testable
+  status: stable
   category: html
   humanReadableName: "Vertical form control support"
   humanReadableDescription: "Enable support for form controls in vertical writing mode"
   defaultValue:
     WebKitLegacy:
+      "PLATFORM(COCOA)": true
       default: false
     WebKit:
+      "PLATFORM(COCOA)": true
       default: false
     WebCore:
+      "PLATFORM(COCOA)": true
       default: false
 
 VideoFullscreenRequiresElementFullscreen: