chore: update Docker configuration and refactor tests

[0x1026]

This pull request includes several changes to improve the project's configuration, testing setup, and code organization. The most important changes include updates to the composer.json file, modifications to the PHPUnit configuration, and adjustments to the Docker setup.

Configuration updates:

• composer.json: Added autoload-dev section for PSR-4 autoloading in the tests directory, updated the PHP requirement to version 8.2, and added configuration options for autoload optimization and plugin allowances. [1] [2]

Testing setup improvements:

• phpunit.xml.dist: Updated the PHPUnit configuration to include XML schema validation, separate unit and feature test suites, and source directory inclusion.
• tests/Feature/ExampleTest.php: Added a basic feature test example.
• tests/TestCase.php: Created a base test case class for PHPUnit tests.
• tests/Unit/DatabaseTest.php: Renamed and updated the namespace for the DatabaseTest class.

Docker setup adjustments:

• docker-compose.yml: Modified the path for the develop service to watch the ./database directory instead of ./docker/database.

Resources

• https://docs.docker.com/compose/how-tos/environment-variables/set-environment-variables/#use-the-env_file-attribute:~:text=Using%20an,your%20project%27s%20directory.