Attempt to automatically fix wireguard issues

[benbjohnson]

When encountering a Wireguard error, the user is sometimes required to restart the agent or run fly wg reset.

Errors can look like:

Pinging WireGuard gateway (give us a sec)... FAILED
(Error: ping gateway: no response from gateway received)

We can't establish connectivity with WireGuard for your personal organization.

or

Error: tunnel unavailable: failed probing "<app-name>": context deadline exceeded

The CLI should automatically try to recover from the error and try again so that users don't have to waste time debugging Wireguard issues when there is a simple fix.