feat: add submissions count to mod dashboard table

[ermish]

Problem

The mod dashboard submissions has more than 20 submissions at the moment, but a moderator wouldn't realize as the result limit is 20, but the page doesn't let the user know

Success

Longer term, we'll want to add pagination to the tables, but for this issue, let's just focus on the results count.

Requirements

• Get the results count from the server response object (see dependencies)
• Show this results count to the user on the pending submissions table
• Show this results count to the user on the approved submissions table
• Show this results count to the user on the rejected submissions table

dependencies

Depends on the server side issue being completed
ourjapanlife/findadoc-server#661