Add GraphQL fields needed for approval widget

What does this MR do and why?

There are some fields missing in the GraphQL API that are needed by the frontend to be able to use GraphQL for the approval widget.

These fields are already present in the REST API endpoints.

This adds the following fields to GraphQL types:

• commentedBy to ApprovalRuleType
• invalidApproversRules to ApprovalStateType

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #389224 (closed)