Premature "trouble processing" error on datatables

[JonellaCulmer]

Related work: #2853

What we're after: While testing the front-end implementation of the 2-year restriction lift, I came across a significant number of errors, particularly when changing the selected filters.

We need to investigate this possible front-end bug a little more to understand why, when a query is still running is a "trouble processing" error displaying in the datatables. It appears that the code (looks like: DataTable.prototype.fetch in tables.js) that triggers the error is "jumping to conclusions" even when it's not necessary for it to display. We see this most often when a user removes a filter criteria during an ongoing or search in-progress.

Preliminary documentation of some of these instances is in the testing notes doc.

Completion criteria:

• Investigate and make a recommendation for a fix
• Fix

[patphongs]

New error states have been drafted within this ticket: #2811 (comment). Closing in favor of that implementation ticket.