Direct insert of nrt_observation_* data

[mpeels]

Description

In order to resolve the race condition between the PostProcessingService and the Kafka Sink Connector for observation data, the ObservationService code was updated to directly persist to the following tables:

• nrt_observation_material
• nrt_observation_coded
• nrt_observation_date
• nrt_observation_edx
• nrt_observation_numeric
• nrt_observation_reason
• nrt_observation_txt

Related Issue

APP-519

Additional Notes

1. The ObservationService.java class was previously responsible for listening for Kafka messages as well as some of the business logic for processing the messages. It has been renamed to ObservationConsumer.java and updated to only validate messages and extract Organization_uid values. The new ObservationProcessor.java class now handles the business logic of processing the data.
2. The NrtObservationWriter is using raw sql upsert statements, with a few more hours work, JPA Repositories could be created with @Entity's defined for each table to handle the insert/update if desired.
3. The previous code had a single class, ProcessObservationDataUtil.java, that was responsible for both parsing the Observation data and posting messages to the relevant Kafka Topics. This was split into an ObservationParser.java and the NrtObservationWriter.java.
4. Resolves a possible thread safety issue where the ObservationKey was declared at the class level but multiple threads were setting its value simultaneously.

Checklist

• I have ensured that the pull request is of a manageable size, allowing it to be reviewed within a single session.
• I have reviewed my changes to ensure they are clear, concise, and well-documented.
• I have updated the documentation, if applicable.
• I have added or updated test cases to cover my changes, if applicable.