Add a warning pop-up when project owners reach the page limit for their subscription tier

[anabasftp]

Project owners can see how many pages they have in the owner dashboard, but sometimes they're not aware of (or they forget about) the page limits for their subscription tier. As a reminder:

• Researchers can upload up to 10,000 pages
• Small Org can upload up to 50,000 pages
• Large Institution can upload up to 100,000 pages

Since there's technically no way for them to be prevented from exceeding their upload limit, a warning pop-up reminding them that they have reached their page limit would be helpful.