Performance issues loading batches

[jinnthehuman]

If the list of batches is very large (the project I tested on had 10k+ batches), the observed behavior is the tab crashes due to an out of memory error or the batches list table reverts to a "no results" state after showing partial results.

I suspect the following things are happening:

1. The plugin is requesting all of the page for batches list during initialization instead of requesting a handful and continuing the request as the user pages through the list.
2. The batch info that the plugin requests are stored in memory, which can grow very large and cause OOM errors.
3. Due to the volume of requests sent in a short period of time, the server returns with a 429 error.