LibWeb: Add {,de}serialization steps for ImageData

Author: https://github.com/kennethmyhra
Commit: 6941b63890
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4596
Reviewed-by: https://github.com/shannonbooth ✅

Tests/LibWeb/Text/expected/HTML/StructuredClone-serializable-objects.txt

@@ -29,3 +29,10 @@ CryptoKey.algorithm: {"name":"PBKDF2"}
 CryptoKey.usages: ["deriveKey","deriveBits"]
 instanceOf DOMException: true
 DOMException: Index out of bounds - IndexSizeError
+instanceOf ImageData: true
+ImageData.width: 2
+ImageData.height: 2
+255, 0, 0, 255
+0, 255, 0, 255
+0, 0, 255, 255
+255, 255, 0, 255