[nwd] Replacing image lib references where necessary
After analyzing appsheets usage of epplus it was found that the only
functionality which interacts with System.Drawing.Common are:
ExcelWorksheet, uses Color functions
ExcelChartsheet, embeds chart image in worksheet.
Worksheet using Compatibility for system.drawing.common so switched the
core compatibility to use ironsoftware.
Worksheets using some image apis.
ExcelVmlDrawingPicture, also switched to use IronSoftware.
These were the only locations that appsheet uses Epplus where
drawing functionality was being implemented.
b/323543312
Change-Id: I68c2951c21f25c25164755f5d5b8839afc5e13e3
9 files changed
