PDF scan button improvement

[jeffpaul]

trafficstars

Is your enhancement related to a problem? Please describe. As @helen noted in https://github.com/10up/classifai/pull/282#pullrequestreview-739987201:

Nice, it's working! We probably need to get smarter with the scan button in a future release, because you can do something like request a scan, switch items, come back, and request another scan. It should probably check the status any time that button is loaded up, or load the button with AJAX entirely.

Describe the solution you'd like

• [ ] check the status any time that button is loaded up //OR// load the button with AJAX entirely

Designs none

Describe alternatives you've considered keep as-is

Additional context