[bionic] Connection issues are not possible to debug in the UI

When using a graphical VPN client, one expects a concise error message, and/or graphical log viewer (specific to the failed connection) to explain what went wrong.

This does not happen when using the OpenVPN gnome plugin. Instead, I have observed two possible behaviors:

(1) A few seconds after toggling the VPN to "on", (after some timeout) the VPN automatically toggles back off, leaving the user with no indication about what happened.

(2) The VPN remains in "on" state but not connected. Instead, it reconnects repeatedly (per the auto-reconnect settings), but continues to fail repeatedly, without any indication to the user that anything went wrong (except for the fact that the VPN never actually connects).

In either case, the only way to troubleshoot the issue is to do something like tail /var/log/syslog.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: network-manager-openvpn-gnome 1.2.10-0ubuntu2
ProcVersionSignature: Ubuntu 4.13.0-25.29-generic 4.13.13
Uname: Linux 4.13.0-25-generic x86_64
NonfreeKernelModules: zfs zunicode zavl zcommon znvpair
ApportVersion: 2.20.8-0ubuntu6
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Jan 18 12:13:53 2018
InstallationDate: Installed on 2017-12-20 (29 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20171219)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: network-manager-openvpn
UpgradeStatus: No upgrade log present (probably fresh install)