Updated a lot of security-related things
- Remove Discovery Service (tons of security-related issues)
- Modified the Gateway Service as reverse proxy
- Upgraded Java 11 to Java 17
- Upgraded Spring 5 to Spring6
- Upgraded packages c3p0, opencsv etc.
Updated non-security related things
- NGINX proxy and
%2Fencoding has issues: default RabbitMQ virtual host is nowdbrepo
Closes #310