connect to openrpt from node-datasource

Requires https://github.com/xtuple/xtuple-server/issues/212

This isn't quite ready for pull. It's still needs some feedback from https://github.com/xtuple/xtuple-server/issues/223

But it's well enough along to start the conversation. This change to the route will expose an API that looks like this:
`https://localhost/demo_dev/generate-report?nameSpace=ORPT&type=AddressesMasterList`
and this:
`https://localhost/demo_dev/generate-report?nameSpace=ORPT&type=AROpenItems&params=startDate:date=%272007-01-01%27`

Is this sufficient for the browerside invocations that we all have in mind?

resolves #1992.
https://github.com/xtuple/openrpt/pull/41 allows:
- replacing `-databaseUrl=psql://host:port/database` with `[-P psql] -h host -p port -d database`
- replacing `-username=name` with `-U name`
- leaving off `-passwd=wxyz` entirely if Postgres is configured to allow password-less login

To connect to a Postgres socket directory, use `-h` with the full path to that directory as the hostname, e.g. `-h /var/run/postgresql`