Adding CSV Appointment Extractor

[dmendelowitz]

Summary

Adds CSVAppointmentExtractor, based on the FHIR Appointment profile.
New template created in AppointmentTemplate.js, new extractor in CSVAppointmentExtractor.js, additional changes to MCODEClient.js, schemas/csv.js, ResourceGenerator.js and various index files to add the new extractor to the client, and necessary test files and test fixtures added.

Testing guidance

Add the following to the config file to test with the appointment extractor:

   {
      "label": "appointment",
      "type": "CSVAppointmentExtractor",
      "constructorArgs": {
        "filePath": "./test/sample-client-data/appointment-information.csv"
      }
    }