Read a laboratory certificate into its rows, each with its page, and check each row against a place's limits

A PDF certificate, or the laboratory's own export as XLSX, XLS or CSV / TSV, read by rules (no AI writes a row): each row the certificate prints with the sample, the parameter, the value as printed, its unit, a qualifier (<, >, ND), the detection limit and the page (or sheet) it was read from; a sample's date, matrix, lab ID and certificate in samples. With a place (best with a medium), every row with a value is checked by check_values itself; exceedances lists every row over a limit or under a floor, each limit once in limits with its cite. A result below detection is not compared (value.below_detection). checked_as is the printed name without the lab's decoration (Cuivre (Cu) a 2 -> Cuivre) when check_value holds that name. Rows page by max_rows / offset (the file is read again). Anything but a PDF, XLSX, XLS or CSV is refused format.not_handled before it is read. The file is read and discarded: it is not kept, and nothing is learned from it.