Merge refactor/config into main

[Kitt3120]

This pull request includes significant changes to the configuration management system, refactoring the code to separate file-based and environment-based configurations. The most important changes include the addition of new modules for handling configurations, the introduction of a trait for merging configurations, and updates to the main application code to use the new configuration structures.

Configuration Management Refactor:

• Cargo.toml: Added serde-env dependency to support environment-based configuration.
• src/config.rs: Removed old configuration management code and restructured to use new modules config_handler, environment_config, and file_config.
• src/config/config_handler.rs: Introduced ConfigHandler struct with methods to load configurations from file and environment, and a Merge trait for merging configurations.
• src/config/environment_config.rs: Created EnvironmentConfig struct to handle environment-based configurations.
• src/config/file_config.rs: Created FileConfig struct to handle file-based configurations and implemented the Merge trait for merging with EnvironmentConfig.

Main Application Updates:

• src/main.rs: Updated to use FileConfig instead of the old Config struct in service initialization. [1] [2]