DashBuilder runtime to Quarkus

Motivation

• As a strategic goal on DashBuilder modernization and infrastructure alignment, we should port DashBuilder Runtime backend to Quarkus;

Goals

• Port Dashbuilder Runtime backend to Quarkus;
• Isolate DashBuilder client-side from Backend with a clean REST API;
• Ideally remove Errai

Acceptance criteria

• The DashBuilder Runtime backend webapp should be a Quarkus app, meaning that running it with `mvn quarkus:dev` will start the application in development mode, providing fast startup time and reloads.

Testing

• No changes in features of the DashBuilder Runtime backend application are expected, so exploratory tests can be performed to check if the old behavior is kept.

Documentation

• We should deliver a blog post covering this new feature;
• Update community docs accordingly