Added function for converting coverage source format to Cobertura xml

[hayleycall]

Summary of the Pull Request

Added function to take in SourceCoverage struct from coverage source format and convert to a format that aligns with Cobertura guidelines as xml output.

PR Checklist

• Applies to work item: Related to these Integrate source-based coverage reporting for Windows #1378, Integrate source-based coverage reporting for Linux #1380.
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

Adds function for converting source format, specifically a SourceCoverage struct to Cobertura XML.

Validation Steps Performed

Test added to manually create XML format vs. reading in a SourceCoverage struct and creating the XML format from that.