Integrate Cobertura format and output as file in coverage container

[hayleycall]

Summary of the Pull Request

Outputs coverage file as Cobertura XML format.

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: test in previous Added function for converting coverage source format to Cobertura xml #1533 PR.
• 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

Continues work of outputting improved source coverage as file(s) alongside block coverage file. This work completes the integration of having a third file be outputted to the coverage container, this file being in Cobertura xml format. It calls the function that converts source coverage data to Cobertura format and outputs it as a file. This file will be able to be used as input in ReportGenerator tool.

Validation Steps Performed

A cobertura-coverage.txt file should be created in coverage container in Cobertura XML format with same data as source-coverage.json file.