Before this change the exit code for transfer limit exceeded was
incorrect. This was because the `resolveExitCode` function unwraps the
error thus reading the underlying error which is not the same as the
error it was comparing to (`ErrorMaxTransferLimitReached`).
This change fixes it by splitting the error definition in two so that
when the Fatal error is unwrapped we match against
`ErrorMaxTransferLimitReached` however when we return the error we
return `ErrorMaxTransferLimitReachedFatal`.