Check on DB date inserts when using insert_dataframe with_copy=True

INSTRM-2833 was about the sps_expsoure table getting UTC dates inserted instead of HST. It was fixed for that particular actor, but the generic issue is still present.

When using opdb.insert_dataframe with_copy=True (which is the current default), there can be issues with the dates being first converted to strings, which can drop the timezone info and be inserted incorrectly.

Investigate when it happens and decide if we want to fix the with_copy behavior, change the default to False, etc.