Fix /api/v1/admin/trends/tags using wrong serializer

[ClearlyClaire]

Fix regression from #18641

[ClearlyClaire]

@Gargron do you mind reviewing this?

[Gargron]

I don't know what I was thinking when designing this controller, but it's using the normal serializer because when the user doesn't have admin scope/permission, it acts like the non-admin controller. Using the admin serializer here would expose extra details to non-admin users.

[ClearlyClaire]

This is an ugly workaround, but I changed it so:

• which serializer is used depends on whether the usage can manage trending tags
• the javascript component doesn't link to anywhere if the id is not serialized

[trwnh]

the javascript component doesn't link to anywhere if the id is not serialized

how does that interact with #21701? if done this way, i feel like you would also need an admin API endpoint to lookup tag id by name... or perhaps checking for one of the other properties?

[ClearlyClaire]

the javascript component doesn't link to anywhere if the id is not serialized

how does that interact with #21701? if done this way, i feel like you would also need an admin API endpoint to lookup tag id by name... or perhaps checking for one of the other properties?

I don't think this whole endpoint is very useful when the user doesn't have the permissions to manage hashtags. AFAICT the only reason there's the fallback to begin with is the admin dashboard that is displayed even if one does not have tag management permissions.