ISSUE: #41 Update Node version for server and dependencies

[brendanarnold]

Addresses issue (#41)

• Cleaned up some config further
• Updated server.Dockerfile to run Node 18.12.1 and latest Alpine
• docker scan polis-server:latest reveals massive reduction in vulnerabilities in dependencies
  • None in Alpine
  • sql depends on a vulnerable version of lodash which currently has no fix
  • @google-cloud/translate depends on a vulnerable verison of taffydb which currently has no fix
• Updated docs
• Google Translate updated to latest and has simpler config
• Migrated Express from v3 to v4
• Removed redundant simple-oauth2 dependency
• Updated eslintrc to a Typescript version
• WARNING Updated Slack dependency but didn't test as plan to remove (#10) - this is a major version bump