Create user-friendly error window for Canvas error {"error":"invalid_client","error_description":"unknown client"}

The LMS app error message generated in Canvas when a developer key has been deleted does not display to the user in the typical user-friendly view:

Error text: `{"error":"invalid_client","error_description":"unknown client"}`

Ideally, we would display for the user an error message in the format as below (example error is generated when a Canvas developer key is turned off):

No files, tests, or entry points are named. Start by reproducing the Canvas developer-key deletion flow and compare the raw invalid_client response with the user-friendly example in the issue. Done means the error is presented to users in a comparable readable format rather than as raw JSON.

Written by the indexing model from the issue text.