Adapt text of moderation emails for all authorities

From issue:

You're right, I didn't address this in a comment.

TLDR (IMO): we can merge this version, and I’ll link to this comment from the board. I already have a vague "Send moderation emails in non-pre-moderated groups" card there, but I reckon most of the work there will be this issue.

The "comment" wording is what bioRxiv wants, so we’ll start with that. This PR only sends emails for pre-moderated groups, which are only offered to bioRxiv, so this will work for them.

Of course, we’ll want to send these in all cases eventually, so we have a few options:

- Use the "comment" wording everywhere.
I don't like this. It would be odd if this were the only place where annotations become comments.

- Convince bioRxiv to use “annotation” instead.
I don't think this is likely.

- Use the "comment" wording everywhere, but just for "page notes".
Not ideal to use both `page note` and `comment` for the same thing, but this would be easy to implement.

- Use different templates or a conditional to show `comment` for bioRxiv and `annotation` for others.
While this seems like the obvious solution, I’m not sure how we’d determine this—by authority? Organization? The group the annotation is in?

_Originally posted by @marcospri in https://github.com/hypothesis/h/pull/9587#discussion_r2111703441_