gh-129374: adds quoting detection to csv sniffer

[aterrel]

• Issue: Feature request: sniff csv quoting and lineterminator #129374

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[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[serhiy-storchaka]

Thank you for working on this, but the sniffer was rewritten on the main branch (gh-83273) and this patch no longer applies.

Detecting quoting would fit in a _detect_*() method for the chosen combination, next to _detect_doublequote(), but it needs to know which fields were quoted, and the reader does not report this. Note also that QUOTE_NONNUMERIC changes how the dialect reads the data: unquoted fields are converted to floats. This is worth deciding in the issue first.