Add TabColor and ColFmtNo support to ParseXLSX

Hello,

This patch adds two new features to ParseXLSX to make it compatible with ParseExcel.  The first commit adds support for getting the tab color of the current worksheet.  The second sets the undocumented ColFmtNo property of Spreadsheet::ParseExcel::Worksheet (see https://metacpan.org/source/DOUGW/Spreadsheet-ParseExcel-0.65/lib/Spreadsheet/ParseExcel.pm#L1367), which stores the column default formats.  I have added tests for both features.  Please let me know if there is anything you'd like me to fix or change.  Thank you and have a great day!

Cheers,
Fitz