Remove unused saved to postgres calls

[BobanL]

What needs to be done

• Remove saveSource from the params of the /save-fhir-data endpoint
• Remove unused saveToPostgres function
• Update api docs for POST /save-fhir-data
• Update orchestration to remove saveSource request parameter

Why it needs to be done

• S3 localstack has replaced the need for saving fhir bundles to postgres

Acceptance Criteria

• [ ] saveSource is removed from POST /save-fhir-data
• [ ] All unused code is removed
• [ ] Orchestration no longer passes in saveSource parameter

Technical Notes

• https://docs.localstack.cloud/user-guide/aws/s3/
• https://docs.localstack.cloud/user-guide/integrations/sdks/javascript/