Clarify relationship to Flight SQL, when to use it, error differences?

this is technically correct -- however I wonder if we want to highlight that it is (also) FlightSQL (which basically is a set of messages on top of Filght)?

_Originally posted by @alamb in https://github.com/influxdata/docs-v2/pull/5115#discussion_r1308699685_

Start with the discussion in pull request #5115 linked from the issue body and locate the documentation wording it discusses. Clarify the relationship to Flight SQL, when it should be used, and how errors differ; done means the relevant documentation addresses those questions consistently.

Written by the indexing model from the issue text.