Interface ParseCsvOptions

Find the header by its column names, in any position: the header is the first row whose cells (trimmed) include at least headerMatchThreshold of these names. A row that misses a few (a renamed column) is still found, so the caller can name the missing ones. Takes precedence over headerFirstCell.

Skip preamble rows until the header is found. If given, the header is the first row whose first cell (trimmed) equals this value; otherwise the header is the first non-empty row. Superseded by headerColumns, which finds the header wherever its columns stand.