BI-2918: Study Cache 1 - Replace programCache.get() dependencies with direct BrAPI calls

[humsika]

Description

Story: BI-2918

Updated BrAPIStudyDAO so Study read paths no longer depend on programCache.get(). The affected methods now retrieve Study data directly from BrAPI using the BrAPI client / DAO utility pattern, similar to the existing cache-removal approach used in BrAPIObservationUnitDAO and Trial DAO.

Main changes:

• Replaced Study cache reads in getStudies(...).
• Replaced Study cache reads in getStudiesByEnvironmentIds(...).
• Preserved existing Study ID behavior by filtering with the BI Study external reference.
• Added/updated unit tests to verify direct BrAPI reads are used instead of programCache.get().

Dependencies

• brapi-Java-ProdServer: feature/BI-2996
• bi-web: feature/BI-2915
• bi-api: feature/BI-2918

Testing

Unit testing:

• Added/updated BrAPIStudyDAOUnitTest.
• Verified Study reads call brAPIDAOUtil.get(...).
• Verified programCache.get(...) is not called.
• Verified Study lookup by environment ID still filters using the BI Study external reference.
• Verified empty BrAPI results return an empty Study list.

Manual testing:

• Verified Experiments tab loads Study/environment data.
• Verified Env, Env Location, and Env Year continue to display correctly.
• Verified new experiment import flow.
• Downloaded an experiment and verified the environment information is still populated correctly, including environment name, environment location, and environment year.
• Appended an observation variable to the top-level experiment dataset and confirmed the import completed successfully.
• Created/used a sub-entity dataset, downloaded it, added a different ontology observation variable, appended it back, and confirmed the sub-entity append flow completed successfully.

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 created/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