Fix integration tests with embedded sqlite and refactoring

[ThaminduDilshan]

Purpose

This pull request introduces significant enhancements to the Thunder project, including the addition of SQLite database support, improved integration test automation, and refactoring of the build and test workflows. Below is a summary of the most important changes grouped by theme.

Database Enhancements

• Added SQLite database support by introducing a new driver configuration (sqlite) and a Path field in the DatabaseConfig struct.
• Created a new SQLite schema file (dbscripts/sqlite.sql).
• Updated the database initialization script to handle SQLite databases.

Build and Test Workflow Improvements

• Refactored the Makefile to separate build and packaging steps, introduced a dedicated .build directory for intermediate artifacts, and added a test target for running integration tests.
• Updated the README to reflect the new make test command for running tests.

Integration Test Enhancements

• Refactored integration test utilities to support SQLite, including replacing the deployment YAML, running the init script, and starting the server with SQLite configurations.
• Updated integration tests to validate additional fields (token_type, expires_in) in OAuth2 token responses.
• Changed the test server port to 8095 and updated related configurations.

Runtime Configuration

• Introduced a ThunderRuntime struct and related methods to manage runtime configurations, such as ThunderHome.

Refactoring

• Refactor the services to utilize thunder runtime and remove config parameter.
• Refactor the db module to utilize a database provider and client.