Expose more picture information

[yicixin]

Description
I'm currently trying to import images from Excel into my online sheet project using excelize. However, the excelize.Picture does not provide information on the image's scaling and offset in Excel, making it impossible to reproduce the image's size and proportion as seen in Excel. After some investigation, I've confirmed that this data is indeed parsed into deCellAnchor.Pic. Would it be possible to expose this data to external?

I understand some of the complexities involved here. The image size recorded in Excel is not in pixels but in EMU units. It requires a determined DPI to convert it to pixels. Directly exposing this data to external users might not be the best approach. However, providing such information is essential. This brings up the consideration of how to implement it elegantly.

I believe there's a need for a more elegant solution, that can help users access this information in a way that's intuitive and useful.