AO3-3730 Add series stats to user dashboard

[ellieyhcheng]

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Issue

https://otwarchive.atlassian.net/browse/AO3-3730

Purpose

The PR adds series bookmarks, subscriptions to the Totals stats block and also adds Series to the list of works.

This is building on top of the work in #5304
I apologize if I have overstepped, but since that PR hasn't been actioned on since Feb, I've gone ahead and applied the refractoring requested by the reviewers, as well as added tests for the StatsController.

I've kept the Types View from upstream, so that series can be viewed separately from works, but let me know if that should be removed.

I've also made the design choice that when sorted by hits, kudos, or comment threads (which series don't have), these stats count as 0 for series.

Testing Instructions

Create test users with series and bookmark and subscribe to the series.

Then the series bookmark and subscription should show up on the stats page. The series will also show up in the list of works.

Types View should show the series grouped separately from works.

References

#5304

Credit

ellieyhc (she/her)

[sarken]

Thanks for working on this, ellieyhc!

The previous contributor deactivated their Jira account, so it's okay that you adopted this -- I've gone ahead and assigned the Jira issue to you. However, for future reference, we ask that contributors contact otw-coders@transformativeworks.org before adopting pull requests that appear abandoned (you can find that info in our Code of Conduct).

[ellieyhcheng]

Understood, thanks for letting me know!