Added transaction projection for transactions - additional channel property

This PR relates to issue: https://github.com/jembi/openhim-core-js/issues/208. It also incorporates issue: https://github.com/jembi/openhim-console/issues/132 as well as issue: https://github.com/jembi/openhim-core-js/issues/190
Please add a permissions check for non admin users. Maybe the best for now would just be to set the representation to `simple` if the user isn't admin. This should be set regardless of what the requester specified.