Allow wrapping using _anonymous_ type

[joente]

Description

Adds the option to write anonymous wrap-only type. It is not possible to use type or enumerators in anonymous type but since nesting is possible, this is not that important. We need to prevent the use of type for caching reasons.

Example:

.wrap(&{
  id: '#',
  name: 'str',
  friends: [{
    id: '#',
    name: 'str',
  }]
});

Next to the &{..} anonymous syntax, an ano() function is also created which accepts a thing. This can be useful if you want to create anonymous type dynamically.

This pull request also implements a generic enum definition, see #429

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Test ano
• Test wrap
• Test type

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• New and existing unit tests pass locally with my changes