Add getOwner() method to FileInfo and Node API

lib/public/files/node.php

@@ -225,4 +225,12 @@ interface Node extends FileInfo {
 	 * @since 6.0.0
 	 */
 	public function getName();
+
+	/**
+	 * Get the file owner
+	 *
+	 * @since 9.0.0
+	 * @return string
+	 */
+	public function getOwner();
 }

lib/public/files/storage.php

@@ -462,4 +462,10 @@ interface Storage {
 	 * @param bool $isAvailable
 	 */
 	public function setAvailability($isAvailable);
+
+	/**
+	 * @param $path path for which to retrieve the owner
+	 * @since 9.0.0
+	 */
+	public function getOwner($path);
 }