Escape formulas in XLSX

[livedo]

This adds an escape_formulas option to the XLSX generating methods in order to avoid formula injection when generating XLSX. The header row is additionally always escaped.

Usage:

SpreadsheetArchitect.to_xlsx(data: [["=1+1"]], escape_formulas: true) #default
SpreadsheetArchitect.to_xlsx(data: [["Safe"]], escape_formulas: false)
SpreadsheetArchitect.to_xlsx(data: [["=1+1", "Safe"]], escape_formulas: [true, false])

[westonganger]

My initial though was that I dont want to burden this library with every single option that axlsx has built in. I almost think you could just manually escape any user inputted string that you think may nefarious.

All axlsx does is check if the cells value starts with an "=" to determine if its a formula. So all you would have to do to escape any user input text is add a single quote to the beginning of the text. Ex. sanitized_val = val.start_with?("=") ? "'#{val}" : val

That being said I am sure many apps simply dont use formulas at all in their spreadsheet so this would actually be a good feature.

I have made a few comments and we can go from there.

[livedo]

@westonganger could you approve the workflows/build to run in this PR?

[livedo]

That being said I am sure many apps simply dont use formulas at all in their spreadsheet so this would actually be a good feature.

Yeah, I'd figure that creating spreadsheets where some of the fields contain direct user input (names and addresses and such) are a big majority compared to use cases that involve formulas, so it would make all the more sense to provide security by default.

[westonganger]

Can we make the headers rows use escape_formulas: options[:escape_formulas] just the same as the data rows