Generate code coverage report in a well-known format

[ligurio]

cbmc-viewer is able to create JSON and HTML reports with code coverage. However, I think it would be more practical to generate a report
in a popular format for code coverage: Cobertura (XML-based) or LCOV (text-based ¹). These formats are supported by many development tools: code coverage visualization (Coveralls, Codecov), ReportGenerator ², Gitlab CI ³ etc.

Footnotes

1. https://github.com/linux-test-project/lcov/issues/113#issuecomment-762335134 ↩

2. https://github.com/danielpalme/ReportGenerator ↩

3. https://docs.gitlab.com/ci/testing/code_coverage/ ↩