feat(tvos): add custom image metadata option for tvos and add missing types for custom metadata properties (#3280)

* fix: add typescript types for custom metadata properties
* chore: add possibility to override image metadata of video playback

---------

Co-authored-by: Olivier Bouillet <62574056+freeboub@users.noreply.github.com>

ios/Video/Features/RCTVideoUtils.swift

@@ -330,4 +330,15 @@ enum RCTVideoUtils {
         item.extendedLanguageTag = "und"
         return item.copy() as! AVMetadataItem
     }
+    
+    static func createImageMetadataItem(imageUri: String)  -> Data? {
+        if let uri = URL(string: imageUri),
+           let imgData = try? Data(contentsOf: uri),
+           let image = UIImage(data: imgData),
+           let pngData = image.pngData() {
+            return pngData
+        }
+        
+        return nil
+    }
 }