[Bug]: Deprecate the ability to add scalar for a ragged column

[rly]

What happened?

Currently, you can call table.add_row to add a scalar value to a ragged column. If the scalar is a string, then the characters of the string are broken up and stored as characters in the ragged column. To prevent this and provide a clearer API, add_row should not allow taking a scalar value to a ragged column.

Fixing this would be a breaking change. We should first deprecate the use of table.add_row to add a scalar value to a ragged column.

Steps to Reproduce

from hdmf.common import DynamicTable
dt = DynamicTable(name="test", description="desc")
dt.add_column(name="col1", description="desc", index=True)
dt.add_row(col1="hello")  # this should not be allowed. only dt.add_row(col1=["hello"]) should be allowed
dt["col1"][:]  # returns [['h', 'e', 'l', 'l', 'o']]

Traceback

No response

Operating System

macOS

Python Executable

Conda

Python Version

3.12

Package Versions

No response