[prime-fhir-converter] Improve useability of FHIR to HL7 library

[JFisk42]

After the first official release of prime-fhir-converter (#7287), there are still a number of tasks to improve the developer experience.

Remaining tasks grouped by type:

• Tech Debt
  • Reduce tech debt and code smells in prime-fhir-converter (Reduce tech debt and code smells in FHIR to HL7 converter #10531)
  • Refactor ConfigSchema and its inheritors to be immutable (Refactor ConfigSchema and its inheritors to be immutable #10580)
  • Validate subtype class inherits from ValueSetCollection (Validate subtype class inherits from ValueSetCollection #18908)
• Builds/Infra/Jars
  • Automate builds (Automate Builds #8230)
  • Determine steps to publish Java JAR to Maven (Determine steps to publish Java JAR to Maven repo #8220)
  • Add dependabot (Add Dependabot #8246)
  • ❌ Determine if need/want to publish a Kotlin JAR (Determine if we need/want to publish a KT JAR #8221)
• Enhancements
• Documentation
  • Document usage of SchemaServiceProvider (Document use of SchemaServiceProvider #8222)
  • Document contribution process (Document Contribution Process #8247)
  • Publish JavaDoc (Publish JavaDoc #8224)