[C++] Rework CSV reader IO around readahead iterator #23156
Description
Following ARROW-6764, we should try to remove the custom ReadaheadSpooler and use the generic readahead iteration facility instead. This will require reworking the blocking / chunking logic to mimick what is done in the JSON reader.
Reporter: Antoine Pitrou / @pitrou
Assignee: Antoine Pitrou / @pitrou
PRs and other links:
Note: This issue was originally created as ARROW-6825. Please see the migration documentation for further details.