Expose user permissions for timelog entries

What does this MR do and why?

Related to #356796.

This MR is a follow up of !83928 (merged).

This MR adds the permissions that the querying user has for each timelog entry.

Screenshots or screen recordings

How to set up and validate locally

• Add some time spent to an issueable
• Run the GraphQL query

query {
  issue(id: "<issuable_id>") {
    timelogs {
      nodes {
        userPermissions {
          adminTimelog
        }
      }
    }
  }
}

MR acceptance checklist

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