Remove fading toasts

Let's remove all of the toast reliance we have, it is very easy to miss, and delivers poor accessibility. Instead, we need to go through each usage, and deliver inline communication of what the toast was previously communicating (or interstitial transient message displays).

The issue names no files, tests, or entry points, so first locate every toast usage in the studio and review how each message is currently presented. Done means replacing each toast-dependent communication with an inline or approved transient alternative that is accessible and preserves the original information.

Written by the indexing model from the issue text.