Excel Support and Short Date toggle

[sujeendran]

Hi, Thank you for building this tool! It is very helpful in my work. I have added few features that are useful for me and thought others also might find some use with it. Please feel free to review the changes and if you find them useful we can merge it.

Changes included:

• Added support for Excel (*.xlsx) file export
• Added an option to toggle short date format while exporting CSV.
• Removed outdated dependency checks in ParquetViewer.csproj file.
• Updated nuget packages.

Disclaimer: I don't think I have extensively tested support for all the data types for excel file export.

[sujeendran]

Closing this request as there were unintended changes to readme files present in master branch. Opened https://github.com/mukunku/ParquetViewer/pull/54 with just the required commits.