Remove HSQL usage, consolidate application.yaml

[JPercival]

The upstream hapi-fhir-jpaserver-starter project made a few changes that make it more challenging to use an hsql database instead of h2. Specifically:

• The jpaStarterDialectProvider in the common config doesn't rely on the same application.yaml properties as the default dialect provider, resulting in different dialects being provided
  • (we should file that as a bug upstream and fix it)
• The driverClassName is defaulted to org.h2.Driver
• The hibernate.dialect is defaulted to HapiFhirH2Dialect

That means that you have to override several different properties in order to configure a new database connection correctly:

• spring.datasource.url (spring can usually auto-detect the rest of the properties from this)
• spring.datasource.driverClassName (unset to revert automatically detecting, override to specify another driver like postgres)
• spring.jpa.hibernate.dialect (unset to revert automatically detecting, override to specify another driver like postgres)

This PR gives up on hsql for the time being, switching back to the default H2. It also provides a new pattern for inheriting and overriding properties:

spring:
   config:
      import: classpath:org/opencds/cqf/ruler/external/application.yaml
---
spring:
   main:
      allow-bean-definition-overriding: true # the cqf-ruler plugins override serveral upstream hapi beans
---
hapi:
   fhir:
      fhir_version: R4
      server_address: "http://localhost:8080/fhir"
      openapi_enabled: true
      tester_enabled: true
      tester:
         home:
            name: Local Tester
            server_address: "http://localhost:8080/fhir"
            refuse_to_fetch_third_party_urls: false
            fhir_version: R4

      ## CQL Settings
      cql:
         # enabled: true
         engine:
            # debug_logging_enabled: false
            options: "EnableExpressionCaching"

This allows you to just import the standard hapi-fhir-jpaserver-starter properties and override only the ones you want to, shrinking down our yaml files.

[JPercival]

Resolves #619