feat(server): role based authentication system (#2434)

- Parse toml configuration file, see https://github.com/qdm12/gluetun-wiki/blob/main/setup/advanced/control-server.md#authentication
- Retro-compatible with existing AND documented routes, until after v3.41 release
- Log a warning if an unprotected-by-default route is accessed unprotected
- Authentication methods: none, apikey, basic
- `genkey` command to generate API keys

Co-authored-by: Joe Jose <45399349+joejose97@users.noreply.github.com>

Dockerfile

@@ -194,6 +194,7 @@ ENV VPN_SERVICE_PROVIDER=pia \
     # Control server
     HTTP_CONTROL_SERVER_LOG=on \
     HTTP_CONTROL_SERVER_ADDRESS=":8000" \
+    HTTP_CONTROL_SERVER_AUTH_CONFIG_FILEPATH=/gluetun/auth/config.toml \
     # Server data updater
     UPDATER_PERIOD=0 \
     UPDATER_MIN_RATIO=0.8 \