Multi module project processing

[hazendaz]

Today, when this plugin runs, it runs for each module. Because the plugin does not start in a well defined folder such as src but rather the root of that level, that means that it will run multiple times against the same files per module. While I have not confirmed that the case, I cannot see how it isn't the case.

Take for example this project, its muti module and runs license under every module.

I've seen multiple plugins that need this sort of behavior now working differently where they only run once at the end.

See https://github.com/SonarSource/sonar-scanner-maven/blob/e2ddfc354744c15f7899b5f029ee49f2b4de0aa0/src/main/java/org/sonarsource/scanner/maven/SonarQubeMojo.java#L159

I think we need to look into this as I think it will help to improve the processing. I've seen open rewrite doing same thing now and I have some uses cases elsewhere that need same behavior.