Reduce workItemNotesByIid query complexity

What does this MR do and why?

Issue: #482512 (closed)

Reduce workItemNotesByIid query complexity

The workItemNotesByIid query exceeded the maximum complexity for anonymous (signed out) users, which is set to 200.

The query had a complexity of 218. By reducing the page size, we reduce that complexity to ~180, which gives us some room in the case we need to query more fields in the future.

Changelog: fixed

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Before	After

How to set up and validate locally

1. Visit a work item as a signed out user
2. Before: notes did not load. After: notes are loading again

How to run the workItemNotesByIid query and see the complexity:

1. Go to http://gdk.test:3000/-/graphql-explorer
2. Paste the following query

Query

query workItemNotesByIid($fullPath: ID!, $iid: String!, $after: String, $pageSize: Int) {
  queryComplexity {
    score
    limit
  }
  
  workspace: namespace(fullPath: $fullPath) {
    id
    workItem(iid: $iid) {
      id
      iid
      namespace {
        id
        __typename
      }
      widgets {
        ... on WorkItemWidgetNotes {
          type
          discussions(first: $pageSize, after: $after, filter: ALL_NOTES) {
            pageInfo {
              ...PageInfo
              __typename
            }
            nodes {
              id
              notes {
                nodes {
                  ...WorkItemNote
                  __typename
                }
                __typename
              }
              __typename
            }
            __typename
          }
          __typename
        }
        __typename
      }
      __typename
    }
    __typename
  }
}

fragment PageInfo on PageInfo {
  hasNextPage
  hasPreviousPage
  startCursor
  endCursor
  __typename
}

fragment WorkItemNote on Note {
  id
  body
  bodyHtml
  system
  internal
  systemNoteIconName
  createdAt
  lastEditedAt
  url
  authorIsContributor
  maxAccessLevelOfAuthor
  lastEditedBy {
    ...User
    webPath
    __typename
  }
  discussion {
    id
    resolved
    resolvable
    resolvedBy {
      id
      name
      __typename
    }
    __typename
  }
  author {
    ...User
    __typename
  }
  awardEmoji {
    nodes {
      ...AwardEmojiFragment
      __typename
    }
    __typename
  }
  userPermissions {
    adminNote
    awardEmoji
    readNote
    createNote
    resolveNote
    repositionNote
    __typename
  }
  systemNoteMetadata {
    id
    descriptionVersion {
      id
      description
      diff
      diffPath
      deletePath
      canDelete
      deleted
      __typename
    }
    __typename
  }
  __typename
}

fragment User on User {
  id
  avatarUrl
  name
  username
  webUrl
  webPath
  __typename
}

fragment AwardEmojiFragment on AwardEmoji {
  name
  user {
    id
    name
    __typename
  }
  __typename
}

3. Set the variables (change fullPath and iid accordingly`:

{
  "pageSize": 20,
  "fullPath": "flightjs",
  "iid": "235"
}

When changing the pageSize from 20 to 30 (previous default) you will see how the query complexity exceeds 200. Setting it to 20 fixes it as the complexity is reduced to 180 (although queryComplexity query itself adds some complexity).