junit: Handling of @Ignore and @Disabled should be consistent

[cl90]

• Concepts ~DisabledTestClassOrMethod should handle @ignore and @disabled equally (see constraint junit:IgnoreWithoutMessage)
• The descriptions of these concepts should be fixed (named labels are not correct)
• They should provide an abstract concept like "IgnoredTest" or "DisabledTest"
• Constraint junit:IgnoreWithoutMessage should require said abstract concept and work with the according labels