[BI-2744] DeltaBreed:Create exp, create obs level

[HMS17]

Description

Story: BI-2744 - DeltaBreed:Create exp, create obs level

Added logic for experimental import to create observation levels for new exp units.

Added validation to check for more than one exp unit in file and return error if so (previous behavior just took the first row exp unit and silently ignored all other rows).

Note: Testing BI-2791 atop experiments made with these changes revealed a niche case where if an import file was made that forcibly included Exp Units of different casings (ie BaconPancakes and BaconPANCAKES), downloading for a particular environment(s) rather than "All Environments" resulted in the download failing due to a null pointer exception because in BrAPITrialService.java:exportObservations, the hash "entry" would get an additional value with a null key for the alternate casing version of the Exp Unit. Since this logic is dependent upon the Exp Unit value stored in additionalInfo, it was determined that the fix should be covered in BI-2778, which will deprecate use of additionalInfo for level, and that case tested there.

Dependencies

bi-web: feature/BI-2744

Testing

• Create experiment file with multiple exp unit values
  -- Attempt to upload file
  -- Error message should appear and file upload should be prevented

• Create experiment file with new exp unit value (not Plot)
  -- Upload file
  -- Ensure Experiment Preview displays the exp unit value as capitalized regardless of what case the value was in file
  -- Confirm Import and ensure file imports successfully
  -- Ensure Experiment Details displays the exp unit value as capitalized regardless of what case the value was in file
  -- Check that the GET /observationlevels call for that program returns the new exp unit value

• Create experiment file with same exp unit value as the first upload
  -- Upload file
  -- Confirm Import and ensure file imports 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 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

[jloux-brapi]

Tested with FB. Endless fetching error has been resolved with this change!