Draft: [DO NOT COUNT THIS ONE] Use UserCallout model to keep track of trial status popover dismissals

❌ Something went wrong

I started this MR and targeted a branch other than master. It started a few master commits ahead of the target branch. When the target branch was brought up to current with those same commits, GitLab assumed I had merged this branch into the target, and so it marked it as merged and now there doesn’t appear to be any way of undoing that.

I’ve redone the branching, this time with both branches fully up-to-date with master before starting, and added the actual commits for this MR to that branch. The new MR is here: !64675 (merged)