copy-paste code refactoring, following IDEA-125021, CR-IC-5751
IDEA-127877 Inspections UI: add description on multiple inspections selection
IDEA-127872 Condition checkbox doesn't remember its state (breakpoint config)
NPE
IDEA-127958 Deadlock in completion
DocumentationManager: allow to pass cancelCallback to completion doc (towards IDEABKL-6124)
inspections ui: Do not show the "Options" section header if there's nothing underneath it.
IDEA-127971 (CollectionDeclaredAsConcreteClass inspection suggests to weaken Properties to 'null')