feat(files): Support ios-asset-id metadata

[artonge]

No description provided.

[marinofaggiana]

@artonge when available ?

[artonge]

when available ?

When you tell me that it works and is enough for you :)

[marinofaggiana]

when available ?

When you tell me that it works and is enough for you :)

The metadata itself looks good to me.

For the iOS background upload use case, however, I think we also need a way to set it directly during the upload, ideally through an upload header, so that the server can store the PHAsset.localIdentifier as files-ios-assetId when the file is created.

It would also be useful to have a way to update or clear files-ios-assetId afterwards for already uploaded files.

So ideally:

• upload header → automatically sets files-ios-assetId
• metadata API → allows setting/updating/clearing it later

Also, I'm not sure if it might be used for Android as well (in the future), so a more generic name: files-asset-id.

Added: It must be visible as a SEARCH dav.