[Feature] Support for flatten view

[h3ndry]

Check list

• I have read through the README
• I have searched through the existing issues

Environment info

• OS
  • Linux
  • Mac OS X
  • Windows
  • Others:

Version

csview 1.2.2

Problem / Steps to reproduce

Thank you for creating such an exceptional application. I frequently need to view CSV files with extended column widths, which unfortunately, do not display well in table view. Therefore, I would like to suggest the implementation of a csview flatten feature, similar to xsv flatten, but with line separation. I believe this enhancement would greatly improve the user experience. Thank you for considering my suggestion.