BI-2979: ObservationUnitDAO Optimization: Utilize searchQuery params instead of full program OU grab and filter

[humsika]

Description

Story: BI-2979

Updated BrAPIObservationUnitDAO to retrieve observation units using BrAPI study/trial search parameters instead of loading all observation units for the program and filtering locally. Added focused unit-test coverage for the updated queries.

Dependencies

bi-web: epic/BI-2862
bi-api: feature/BI-2979
brapi-Java-ProdServer: epic/BI-2862

Testing

1. Open Experiments & Observations and select an experiment containing observation units.
2. Confirm:

• The experiment details page loads successfully.
• The germplasm count is correct.
• Only observation-unit data belonging to the selected experiment is displayed.

3. Open a different experiment and confirm its counts and rows are correct and are not mixed with the first experiment.

Checklist:

• I have performed a self-review of my own code
• I have tested my code and ensured it meets the acceptance criteria of the story
• I have create/modified unit and/or integration tests to cover this change or tests are not applicable
• I have commented my code, particularly in hard-to-understand areas
• I have either updated the source of truth or arranged for update with product owner if needed https://breedinginsight.atlassian.net/wiki/spaces/BI/pages/1559953409/Source+of+Truth