OpenXML: Hidden cells shouldn't be translated by default

The default behavior of the filter is to exclude hidden text, with an option to translate it. However, for XLSX we translate hidden cells by default and have no option.

We should align the default behavior with the rest of the filter by excluding hidden cells by default, and add an option to support their translation.

Cells can be excluded either by hiding a row or hiding a column. Both of these are handled in the worksheet markup. For columns, it's defined in a column header:

#!xml
  <cols>
    <col min="1" max="1" width="21.1640625" customWidth="1"/>
    <col min="2" max="2" width="36.83203125" hidden="1" customWidth="1"/>
  </cols>

For rows, they're on the row data themselves:

#!xml
    <row r="2" spans="1:2" hidden="1">