parser-js: Some schemas are never iterated

Describe the bug

The following schemas are never iterated and therefore are never assigned ids.

• Standalone component parameters
• Standalone component traits with headers

How to Reproduce

The following yaml file should give parameters and headers uids.

asyncapi: 2.0.0
info:
  title: My API
  version: '1.0.0'
channels: {}
components:
  parameters:
    testParam:
      schema: 
        type: object
        properties:
          name:
            type: string
  messageTraits:
    extension:
      headers:
        type: object
        properties:
          some-common-header:
            type: string

Expected behavior

Expected schemas to iterated