Allows to disable getting default attributes for a type

There was use case where not inheriting default attributes for a specific type became necessary. This is to not clutter types that do not really share basic attributes with most others.

Use the following declaration to disable the inheritance for a specific type.

```
---
inherit: false
```

This is non-invasive change, all existing uses should not be affected by this. This allows to annotate a type explicitly to not get attributes from the type defined in the `_default.*` file.