Full support for multi-module projects

[thsaravana]

For multi-module project we can have two cases:

1. The jacoco report is consolidated and we have only 1 coverage.xml
2. Each module has it's own coverage.xml

For both the cases, the jacoco-report action works, but it could be made better:

• the report doesn't show coverage for each module Ability to Combine Coverage Reporting for Matrix jobs #28 ,
• if the files list is huge, then the PR comment generated will also be huge,
• the paths input takes multiple reports, but we don't have wildcard support for this input Wildcard in report paths? #20 ,

What is considered as a module?

• If we have only one coverage.xml file referred in paths, then treat each <group> (if it exists) in the report as a module. If there are no <group>s, then treat it as a single module project.
• If the paths contains multiple coverage.xml file, then treat each report as a module.
• If the paths contains multiple coverage.xml file, and each report in turn contains <group>, then treat the report as a module. Either flat out the <group> or treat each <group> as a sub-module.

Things to do:

• Add capability to segregate coverage info module wise
• Add rendering capability to create the comment with coverage for modules
  • Show coverage for full project
  • Breakdown coverage module wise
  • Show coverage for files under each module. Have this collapsed by default and users can expand if wanted.