AO3-7382 Making the history page for a nonexistent user show an error 404 instead of redirecting

[ASalbenblatt]

Pull Request Checklist

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Issue

https://otwarchive.atlassian.net/browse/AO3-7382

Purpose

When visiting the history page of a nonexistent user, it used to redirect you to a page saying "Sorry, you don't have permission...", but since the page is in fact nonexistent, it now instead redirects to a 404 page, and only existing users you don't have permission to view redirect to the "Sorry, you don't have permission..." page.

I also i18n-ed the history page's controller while I was at it.

Testing Instructions

In addition to the test in Jira:

1. Log in as a non-admin user
2. Go to a different user's history page
3. You should see a "Sorry, you don't have permission..." error
4. Go to your own history page
5. You should see the normal page

Credit

FlyingFalcon (they/them)