[Webinterface] Re-enable E2E test once metadata is uploaded to tangle quickly.

[jfarago]

The tests were disabled because during the upload , the file initially comes back as "not found" because it hasnt been uploaded to the tangle yet.

The reason this was not an issue before because of how we were deriving the metadata. Now that we support resuming uploads, the metadata needs to be derived from the handle.

[CKH4]

This should be addressed in streamable by polling for the metadata chunk before emitting the event for when passing chunks to the brokers has finished