Fix 3859 Added support for oneOf and anyOf in array sample

[PavelStefanov]

Motivation and Context

Fixes #3859

Description

Added support for oneOf and anyOf properties in array sample.

schema:
  type: array
  items:
    oneOf:
      - type: string
      - type: integer

schema:
  type: array
  items:
    anyOf:
      - type: string
      - type: integer

it will look like this

[
  "string",
  0
]

Also fixed examples for array items.

schema:
  type: array
  items:
      oneOf:
        - type: string
        - type: integer
      example:
        - oranges
        - 15

before

[
  [
    "oranges",
    15
  ]
]

now

[
  "oranges",
  15
]

Types of changes

• No code changes (changes to documentation, CI, metadata, etc)
• Dependency changes (any modification to dependencies in package.json)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[hkosova]

Just FYI, this example is not really valid

schema:
  type: array
  items:
      oneOf:
        - type: string
        - type: integer
      example:
        - oranges
        - 15

It means an array item can have the literal value ["oranges", 15]. So the rendering of this as a nested array is correct.

Multi-item examples (aka whole array examples) should be on the array level, not under items

schema:
  type: array
  items:
      oneOf:
        - type: string
        - type: integer
  example:
    - oranges
    - 15

Atomic item examples can be defined like so:

  items:
      oneOf:
        - type: string
          example: oranges
        - type: integer
          example: 15
      example: oranges

[PavelStefanov]

@hkosova thank you for the clarification. I removed changes for examples and fixed tests