Prompt admin to re-enter API token when decryption fails

[mlwilkerson]

The plugin stores secrets like the API token, in the WordPress db, after encrypting them. The encryption key is determined by the WordPress server environment where the API token is saved.

If the database were to be backed up and then restored to into a new environment, where there's a different encryption key, then any of those secrets encrypted with the former key cannot not be decrypted on the new server. That's a security feature.

However, right now, it can be a bit like finding a needle in a haystack to track down that this is the cause of an error that manifests in, say, the Icon Chooser showing a generic failure message and the WordPress REST API endpoint request resulting in an HTTP 500 status.

An alternative: when a secret is found that cannot be decrypted, bubble up an error message that prompts an admin user to simply re-enter their API token.

[scottsawyer]

I haven't dug into this yet, but it would also be a nice enhancement to provide the API token via a hook so we could use an env variable or at least hardcode in wp-config.