minItems, maxItems and RAML's uniqueItems are missing

[deiteris]

minItems, maxItems and uniqueItems aren't displayed in the API Console.

The following RAML reproduces the issue:

#%RAML 1.0

title: Example API
version: v1
mediaType:
  - application/json

/example:
  get:
    body:
      type: object
      properties:
        customArray:
          type: array
          minItems: 1
          maxItems: 7
          uniqueItems: true
          items:
            type: string

The properties appear correctly in AMF graph under shacl:minCount, shacl:maxCount and raml-shapes:uniqueItems.

I may suggest the following fix deiteris@aa2bc69, but I see that Namespace.js in amf-helper-mixin lacks some properties, so the issue is a bit more complex.

After the fix, the declared array property looks as follows: