Set up a testing container for API endpoints with mock PostgreSQL database

[agennadi]

Context

• Currently, we lack an isolated environment to reliably test our API endpoints with mock PostgreSQL data. We need to set up a testing container for this purpose.
• The mock data currently doesn't include Geometry data. We need to find a way to insert Geometry data in the mock database.

Definition of Done

• The testing container (standard Docker container or Testcontainers) is integrated into the project.
• Mock data with Geometry columns is successfully loaded.

Engineering Details

• backend/database/init.sql is a sql script that should be executed to populate a testing db with mock data. This script should be modified to insert data of types Point, Polygon, and Multipolygon.
• There are two ways to create a testing container: 1) use a standard Docker container; 2) use Testcontainers library to programmatically spin up and tear down a mock PostgreSQL database.