Graphql: Introduces meeting_metadata

[gustavotrott]

Add to graphql meeting /create params sent with prefix meta_.
https://docs.bigbluebutton.org/development/api/#create

query {
  meeting_metadata {
    name
    value
  }
}

query {
  meeting {
    meetingId
    metadata {
      name
      value
    }
  }
}

[sonarcloud]

Quality Gate passed

Issues
24 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.4% Duplication on New Code

See analysis details on SonarCloud