AO3-6779 Log work language edits by admins as language edits

[slavalamp]

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• Have you added tests for any changed functionality?
• Have you added the Jira issue number
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Issue

https://otwarchive.atlassian.net/browse/AO3-6779

Purpose

Makes it so when superadmins/PAC admins edit a work language, it gets logged as an "edit language" action with old and new languages in the summary (instead of an "update tags" one with no language info)

Credit

slavalamp

[slavalamp]

The ticket doesn't mention the scenario of both the work language and some tags being changed, even though that's technically possible, and I'm not sure what a good way to account for that would be, so I haven't tried doing that here