[Drive] migration from old drive

[rezk2ll]

• create a migration tool for PHP drive files to the new drive in Node.
• add a message in the frontend new Drive that detects if we are in canary and shows like "This is the new Drive, your documents are not migrated here yet, you can exit canary to see all your previous documents. Documents added here will not be visible yet on production but will be kept after the final migration."