[Feature]: Warn to use index argument on call to add_trial (or add_row)

[CodyCBakerPhD]

What would you like to see added to PyNWB?

From https://github.com/NeurodataWithoutBorders/helpdesk/discussions/71#discussioncomment-8638454

User was confused by HDMF level error during io.write. Caused by not declaring a column to be 'indexed' and giving it ragged input across different rows (which worked fine to add to the in-memory NWBFile object)

Is your feature request related to a problem?

No response

What solution would you like?

Warn or error on trying to add the value while still in-memory rather than waiting until writing to disk

Do you have any interest in helping implement the feature?

No.

Code of Conduct

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• [X] Have you checked the Contributing document?
• [X] Have you ensured this change was not already requested?