Rename variables in docker installation

[prasadtalasila]

The .env file has the following format:

DTAAS_DIR='/User/xxx/DTaaS'
SERVER_DNS='foo.com'
OAUTH_URL='http://foo.com'
CLIENT_ID='xxx'
CLIENT_SECRET='xxx'
OAUTH_SECRET='random-secret-string'
CLIENT_CONFIG='/User/xxx/DTaaS/deploy/config/client/env.trial.js'
username1='user1'
username2='user2'

While the names of CLIENT_ID and CLIENT_SECRET are technically correct from OAuth providers point of view, they are confusing to the admin of DTaaS. From admin's point of view, these are variables for traefik forward-auth and probably renamed to SERVER_ID and SERVER_SECRET.

[prasadtalasila]

It is also better to rename deploy/config/lib.docker to just deploy/config/lib