feat: iOS apps append text at cursor

Author: dcalhoun

ios/Sources/GutenbergKit/Sources/EditorViewController.swift

@@ -297,6 +297,14 @@ public final class EditorViewController: UIViewController, GutenbergEditorContro
         evaluate("editor.setMediaUploadAttachment(\(media));")
     }
 
+    /// Appends text at the current cursor position in the editor.
+    ///
+    /// - parameter text: The text to append at the cursor position.
+    public func appendTextAtCursor(_ text: String) {
+        let escapedText = text.addingPercentEncoding(withAllowedCharacters: .alphanumerics) ?? text
+        evaluate("editor.appendTextAtCursor(decodeURIComponent('\(escapedText)'));")
+    }
+
     // MARK: - GutenbergEditorControllerDelegate
 
     fileprivate func controller(_ controller: GutenbergEditorController, didReceiveMessage message: EditorJSMessage) {