Testing / enhancing oauth integration

[bodom0015]

Problem

SSO is fragile and/or not working. We would like to harden this a bit and add some level of support for logging in with CILogon.

Fixes #254

Approach

• Support oauth2 proxy + Keycloak + CILogon configuration
• Add a new endpoint that will validate the _oauth2_proxy cookie / session data and use it to ensure that an account is created for the user in Workbench, then issue a JWT for the user
• Add logic in the dashboard UI module that will send the _oauth2_proxy cookie to the new endpoint mentioned above if the user reaches a protected part of the dashboard without a valid JWT

Other minor changes include:

• Speed improvements for apiserver and gui Docker image builds
• Upgrade ng-base Docker image from xenial -> focal (Ubuntu 20.04 LTS) and carbon -> erbium(NodeJS 12 LTS)
• Cut down on the ambient apiserver container log spam
• Wait for etcd to finish its own container startup before continuing apiserver startup

How to Test

See nds-org/workbench-helm-chart#24 for test steps