Meta targets - class, property, method, ...

[mabar]

Validate if each of them is defined above valid target

• [x] Rules - only above property
• [ ] Callbacks - above class or property (all of them)
• [ ] Modifiers - above class or property (each individually)
• [ ] Docs - above class or property (each individually)

While annotations and attributes validate their targets, we should have an independent way, because:

• each annotation/attribute has to set target individually
• possible other meta sources do not have such option

[mabar]

Annotations/attributes have DefinitionTester for tests