Add the ability to export STIGs and SRGs as XCCDF, CVS, XLSX, MD, JSON

[aaronlippold]

As a user I may need to use STIG and SRG data in multiple formats, allow me to export STIGs and SRGs as:

• XCCDF XML
• CSV
• XLSX
• Markdown
• JSON

Also, allow me to include and exclude 'rows or columns' as fits what data I need.