Improve visual separation between header and body in classes with multiline headers (#10085)
* Add hardline for a class whose extends part is broken
refactor
Use groupId
Remove isPreviousLineEmpty
* Avoid leading comments
* Rename to heritage
* Add heuristic for implements
* Fix lint problems
* Fix
Fix
Fix
* Extract getGroupId patterns
* Adopots solution 2
* Fix
* Fix lint problem
* Add changelog
* Address reviews
* Update tests
* Rename to createGroupIdMapper
* Split files
* Add tests for complex extends
* Fix changelog