WIP: Add Comment Count to Video Preview Components

[RF9A5V]

Description

For backend changes, I added a migration that adds a commentCount column to the video table.

The migration:

1. Creates a column for commentCount on the "video" table that is at first nullable
2. Batches all videos in groups of 1000 to populate the actual values of comment counts for existing data
3. Sets default value of commentCount to 0 for future videos after population
4. Enforces presence of commentCount after population

From there, I've also updated the video comment model to add triggers for events that impact visibility of comments on a video, with those being:

• Creating a comment
• Deleting a comment
• When a comment becomes held for review

At this time, I think I've missed the case when we ban/unban or delete a user, will try to find remaining cases if the approach seems sound so far.

From there, also added the commentCount field to the video model and made the field visible by adding it to relevant formatter definitions.

Front end changes are less significant, just some setup to allow the commentCount to come through from the API, then the UI changes to display the value.

Also added commentCount to the displayOptions, but tbh I still need to dig further into that. Still not sure exactly how this bit works yet, but it seems reasonable to have the commentCount as an optional display, would just need to trace the behavior and implement.

Related issues

Resolves #492

Implements UI based on screenshot provided from #3166

Has this been tested?

• 👍 yes, I added tests to the test suite
• 💭 no, because this PR is a draft and still needs work
• 🙅 no, because this PR does not update server code
• 🙋 no, because I need help

Some manual testing at this time does show the comment count coming through, but still need to implement unit tests.

Screenshots