Delete error alert flow could be improved

At the moment the delete error alert flow fails to do the following:
* Inform which items failed on deletion.
* Associate the failure to delete with the item that failed.

This is understandable, and ultimately a result of the fact that the current alert mechanism solely relies on `toast` notifications. The current implementation of toast notifications is not sufficient in solving for either of the issues outlined above, for two reasons:
* Limited space, so batching and displaying *which items failed and why* in a toast looks broken pretty quickly.

https://user-images.githubusercontent.com/12119389/129155736-ebe87cb7-54c3-4f4c-b6f7-97a08803711e.mov

* Adding *many* toasts (upwards of 25) is both computationally expensive and also a painful user experience.

All that said if we intend to address or solve for the issues with the deletion alert flow addressed above, I believe we'll need a UX pattern that doesn't exclusively lean on toast notifications.

The issue describes shortcomings in the delete error alert flow and its toast-only notifications, but names no files, tests, or entry points. First clarify the intended UX pattern and acceptance criteria for identifying failed items and their errors; done should include a defined solution that handles many deletion failures without relying exclusively on toasts.

Written by the indexing model from the issue text.