Allow indexing on Request/Response properties

[inexorabletash]

There's discussion over in w3c/ServiceWorker#863 (comment) about allowing Request/Response objects to be stored in Indexed DB. That basically just requires defining serialization for them - a blob plus some metadata.

However, like we do for File and Blob objects, we may want to support indexing on properties - see the table in: https://w3c.github.io/IndexedDB/#key-path-construct

(This is necessary since the keypath evaluation algorithms intentionally bypass the prototype chain to avoid invoking getters after cloning.)

[SteveBeckerMSFT]

TPAC 2024: Filed an issue in the Service Worker WG to revisit this issue, looking for current use cases for serializing Request/Response in IDB.