* Pivot Exports/Downloads Should Not include pivot-grouping or 'Extra' Rows

Fixes 46561

When downloading a pivot table's data, a column 'pivot-grouping' is included as well as 'extra' rows that correspond
to various totals in the table.

This PR removes the pivot-grouping column and any of these 'extra' rows from the downloads/exports.

* fix xlsx

* Fix csv

* fix json

* add test and fix some failing tests

* fmt

* Update src/metabase/query_processor/streaming/csv.clj

Co-authored-by: metamben <103100869+metamben@users.noreply.github.com>

* static viz table renders filter out pivot-grouping

* address review feedback

* add some comments to try explain the changes

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Co-authored-by: metamben <103100869+metamben@users.noreply.github.com>