feat: add support for repeatable link values

[levimykel]

Resolves: Repeatable links project

Description
The second of 3 PRs to support an array of links as well as single links. It would allow devs to not manually wrap their link in a Group. It would also allow editors to have a better experience with a dedicated UI for multiple links.

This PR handles the link value changes. Links can now be an array of links or a single link (as they've always been in the past). This is set via the repeat property in the link model (see PR 1)

Here's what to expect from the output of API v2:

// repeat: false
{
  "example_link": {
    "link_type": "Web",
    "url": "https://prismicio.io",
    "text": "Visit Prismic!",
    "variant": "primary"
  }
}

// repeat: true
{
  "example_links": [
    {
      "link_type": "Web",
        "url": "https://prismicio.io",
        "text": "Visit Prismic!",
        "variant": "primary"
    },
    {
      "link_type": "Web",
        "url": "https://prismicio.io/docs",
        "text": "View the Prismic docs",
        "variant": "secondary"
    }
  ]
}

Other PRs

• 1 - Add support for repeatable links in models
• 3 - Support repeatable links in helpers & migration

Note

Until PR 3 is merged into this PR, the tests will fail.

Checklist

• If my changes require tests, I added them.
• If my changes affect backward compatibility, it has been discussed.
• If my changes require an update to the CONTRIBUTING.md guide, I updated it.

Preview

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