[BI-2816] Unknown error when creating new exp with more than one exp title

[HMS17]

Description

Story: BI-2816 - Unknown error when creating new experiment with file with more than one experiment title and at least one title is that of an existing experiment

Fix to move checking for multiple experiment titles on experiment creation earlier, to avoid problems when at least one of the multiple experiment titles was existing and one was new, where PopulateExistingPendingImportObjectsStep.java ended up attempting to populate information for rows without the existing title which was resulting in an Unknown Error.

Dependencies

bi-web: develop

Testing

Import experiment file for new experiment:

• with multiple exp title, all new: should get error saying multiple experiment titles
• with multiple exp title, at least one existing: should get error saying multiple experiment titles
• with one exp title, already existing: should get error saying exp title already exists
• with one exp title, new: should be able to import without issue

Also repeat above tests with adding new environment to existing experiment via the create experiment workflow

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

[davedrp]

Passed test.
Passed Code Review.