Improve error messages related to Jetpack connection

[kean]

The app displays errors directly as they come from the backend, which sometimes results in cryptic messages. The details are welcome because it provides the user with something that they can search for online or refer to when contacting support. However, in some scenarios, the app could also show a link to https://jetpack.com/support/reconnecting-reinstalling-jetpack/ and/or https://jetpack.com/support/getting-started-with-jetpack/troubleshoot-jetpack-connection-error-messages/, which is a common step that the support asks the user to perform to resolve some of these issues.

[dangermattic]

Thanks for reporting! 👍