AO3-7326 Add username to Statistics page title

[ayasayadi1]

Pull Request Checklist

• Have you read "How to write the perfect pull request"?
• Have you read the contributing guidelines?
• Have you added tests for any changed functionality?
• Have you added the Jira issue number
  as the first thing in your pull request title (e.g. AO3-1234 Fix thing)
• Do you have fewer than 5 pull requests already open? If not, please wait
  until they are reviewed and merged before creating new pull requests.

Issue

https://otwarchive.atlassian.net/browse/AO3-7326

Purpose

Adds the username to the browser page title of the Statistics page

Testing Instructions

1. Log in as any user
2. Go to the Statistics page /users/{username}/stats
3. Confirm the page title shows {username} - Stats | Archive of Our Own

Credit

Aya Sayadi (she/her)

[Bilka2]

Hi, Aya Sayadi!

Thank you so much for this pull request. Someone will be along to review it soon.

I've updated the Jira issue status to In Review so no one mistakenly creates a duplicate pull request. If you'd like the ability to comment on, assign, and transition issues in the future, you're welcome to create a Jira account! It makes things a bit easier for us on the organizational side if the Full Name on your Jira account either closely matches the name you'd like us to credit in the release notes or includes it in parentheses, e.g. "Nickname (CREDIT NAME)."

Once you've done that (or if you've already done it -- Jira has been unreliable about showing us new accounts in the admin panel lately), you can either reply here or send an email to otw-coders@transformativeworks.org with your account name and email address and we'll set up the permissions for you.

Thanks again for contributing! If you have any questions, you can contact us at the same email address listed above.