Feature/ci-cd

Add CI/CD to backend

Feature: This MR adds CI/CD functionalities to the backend repository.

Related issues: Closes orientacao-bucal-no-envelhecimento-wiki#18 (closed)

👉 Created AWS infrastructure

👉 Created dockerfile

👉 Improved docker-compose

👉 Created ci/cd pipeline (stages: test, build, push and deploy)

We might want to deploy to different environments in the future (e.g. homolog / prd)