add restore clearnet button. Closes: #5726
add null checks, fix error on get_default_device. Closes: #5732

Also:

-make firewall aware of restarts, and not tear down the fw if an error
 happens while a restart is going on.

-notify errors to syslog.
catch openvpn unexpected ending

show also the back-to-clearnet button on that case.
fix status errors during first eip connection

- show eip button
- update systray action
- remove the provider update on disconnection.
tear down fw on cold starts. Closes: ##5727