`fhir` resource functions

Description

When working with FHIR resources, we can create helper functions to simplify common tasks such as resource extraction, transformation, and conversion.

Examples:
Resource Extraction:
extractResource(bundle, resourceType): Given a FHIR bundle and a resource type, this function would extract all resources of the specified type from the bundle.

Resource Searching:
searchResources(bundle, searchCriteria): Searches for resources in a bundle based on specific criteria (e.g., based on a certain field value).

Resource Conversion:
convertResourceToFhir(resourceObject): Converts a resource object (e.g., a JavaScript object) into a FHIR resource representation and vise versa

Resource Filtering:
filterResources(bundle, filterFunction): Filters the resources in a bundle based on a custom filtering function.

Additional Context

This is the request from our community member @mahaomolise92
See the topic here https://community.openfn.org/t/fhir-helper-functions/354

No files, tests, or entry points are named. Start by reviewing the FHIR helper examples in this issue and the linked community topic, then locate the adaptor code that handles FHIR resources. The scope and acceptance criteria need to be agreed before completion can be assessed.