Create SPHR export module.

[awatson1978]

Requested Feature

Add a new exporter, to patient record in a heterogenous mix-mode NDJSON format with .phr extension, per the Standard Personal Health Record implementation guide.

New-line delimited JSON is a terse flavor of JSON, initially supported by the Bulk Data IG and now included in IHE export, that has advantages when streaming data or when dealing with tens of thousands of records.