Add check-empty-type support to explicit load calls.

[eigood]

If "load" is requested from the moqui cli, then all given data load types are always run. However, if moqui is started normally, it has special support to load certain data items only the first time, when the database is empty(checked via looking for Enumeration records).

This feature lets one specify check-empty-types, and load types. Then, always call "load" in the deployment process, and the first time through(empty database) it'll load seed,seed-initial, etc, and subsequent calls will just load seed.