feat(storage): restore soft deleted object using restore token for HNS buckets

[shubhangi-google]

Add support for restore token to soft deleted from HNS bucket.

Operation Supported:

• If a restore token is provided as an input to restore_file method along with flename and generation token, it will restore seamlessly.
• If restore token is provided, the method calls works as earlier filename and generation token.
• Invalid restore tokens will result in a 404 Not Found error from the Storage Transfer API.

 @example
require "google/cloud/storage"
storage = Google::Cloud::Storage.new
bucket = storage.bucket "my-hns-bucket"
bucket.restore_file "path/of/file", <generation-of-the-file>, "<restore_token>"

[JesseLovelace]

We decided not to add this feature to the client libraries, and to direct customers to use the CLI or console instead