Find mocks that stub every non-private method of their type

Marks a Mockito mock whose every non-private method is stubbed for a single test, counting setup methods and field initializers of its class and of the classes enclosing an inner @Nested class. Such a mock replaces the real type, so the test verifies only its own stubbing. Inherited methods count; Object methods, static methods and constructors do not. A type with a single such method is not marked.