Operation to remove a file from one or more pillars in a collection
The operation request have a field for providing the pillar who is asked to delete the file with a checksum to verify that it is the correct file it is about to delete.
If the provided checksum does not match actual checksum of the file the pillar should not delete the file an end the operation with an error status.
The operation request has a field for requesting a checksum calculation of the file to be deleted which should be provided to the client in the end of the operation via the final response.
If a pillar is unable to respond to a certain checksum request it should reject the request with an error. A pillar could be unable to answer such a request because it does not have any files (the pillar is a checksum pillar) or the specified checksum type is not supported.