feat: expose additionalProfiles field to the social settings

[colis]

What

This PR exposes the additionalProfiles field to the social settings, i.e.

rankMathSettings {
    meta {
      social {
        facebookPageUrl
        twitterAuthorName
        additionalProfiles <----
      }
    }
  }

Why

The Rank Math plugin allows us to add other social profiles apart from the Facebook URLs and the Twitter username. Therefore this field needs to be added to the GraphQL schema.

How

Testing Instructions

1. From the Rank Math Settings -> Titles & Meta -> Social Meta
2. Add a single URL or a list of comma-separated URLs to the Additional Profiles field
3. Use the query above in the GraphiQL IDE

Additional Info

Checklist:

• [x] My code is tested to the best of my abilities.
• [x] My code follows the WordPress Coding Standards.
• [x] My code has proper inline documentation.
• [x] I have added unit tests to verify the code works as intended.
• [ ] The changes in this PR have been noted in CHANGELOG.md

[colis]

Thanks so much for this PR @colis 🙌

Do you think you would be able to add some unit tests for this? If not, no worries it just means it'l take a week or two before I can merge/trigger a release.

(I'm currently overseas on-location for a client and won't be able to dive in too deeply until I'm back.)

hey @justlevine, no worries 🙂

I've updated the existing unit tests, let me know if that's good enough.

Cheers