FHIR integration POC

[amitaibu]

Added a FHIR integration module, that upon creation or update of data, it uploads it to a FHIR datastore.

1. A child's height is created or updated

2. An HTTP request sends the relevant info. No duplicates are created, so only a single patient or observation would be created.

3. Observation created on Google cloud. It references our Patient

4. And we have the Patient as well

Current PR assumes running it locally with DDEV, so one would need to have the following info under settings.ddev.php (ping me to get the real values, as the ones here are dummy, for security reasons):

$conf['hedley_fhir_private_key'] = "-----BEGIN PRIVATE KEY-----\nMIIEvQIBADA...Ce3McVRrHyM=\n-----END PRIVATE KEY-----\n";
$conf['hedley_fhir_service_account_email'] = '[email protected]';
$conf['hedley_fhir_project_id'] = 'bar;
$conf['hedley_fhir_location'] = 'us-central1';
$conf['hedley_fhir_dataset_id'] = 'some-dataset';
$conf['hedley_fhir_fhir_store_id'] = 'some-fhir-store';