MYST-324 Return "Service Unavailable" when ipify is unavailable

[donce]

No description provided.

[Waldz]

Should not logs be handled in connection manager, and it it could have more detailed logs on intermediate steps

[Waldz]

At least, we applied this approach in other places

[donce]

There is no convenient way to log all connect errors in connection manager - take a look at it's implementation:

func (manager *connectionManager) Connect(consumerID, providerID identity.Identity) error {
	if manager.status.State != NotConnected {
		return ErrAlreadyExists
	}

	proposal, err := manager.findProposalByProviderID(providerID)
	if err != nil {
		return err
	}

	dialogEstablisher := manager.newDialogEstablisher(consumerID)
	manager.dialog, err = dialogEstablisher.EstablishDialog(providerID, proposal.ProviderContacts[0])
	if err != nil {
		return err
	}

	vpnSession, err := session.RequestSessionCreate(manager.dialog, proposal.ID)
	if err != nil {
		return err
	}
	manager.sessionID = vpnSession.ID

	manager.openvpnClient, err = manager.newVpnClient(*vpnSession, consumerID, providerID, manager.onVpnStatusUpdate)
	if err != nil {
		manager.dialog.Close()
		return err
	}

	if err := manager.openvpnClient.Start(); err != nil {
		manager.dialog.Close()
		return err
	}
	return nil
}

There are 6 places where error can occur - I want to log all of them, but adding 6 log statements just because this class did not have any logs before doesn't make sense to me.