Capture patient preferred language

[cragun47]

Describe the bug
Add capability to find and convert the following patient information

• Patient.communication.language, Patient.communication.preferred / PID-15
  (Moved from Improve patient information capture #94)

To Reproduce
Create a sample HL7V2.6 patient PID segment with aforementioned patient information.

Expected behavior
Patient information should be detected and added to corresponding fields in HL7 FHIR resources.

Examples:

Communication language: recommended based on ISO table 639. However ISO 639 has additional versions. This is a CWE encoding.

  "communication": [
    {
      "language": {
        "coding": [
          {
            "system": "urn:ietf:bcp:47",  << May not be this system.
            "code": "nl",
            "display": "Dutch"
          }
        ],
        "text": "Nederlands"
      },
      "preferred": true
    }
  ],

Screenshots
N/A

Additional context
Add any other context about the problem here.

[LisaWellman]

In Release 1.0.9