Add Generic FTP/SFTP Connector Classes

[atm-quentin]

Feature Request

This feature request suggests creating generic FTP/SFTP connector classes that can be used across multiple modules in Dolibarr, simplifying and centralizing the file transfer operations.

Use case

Currently, FTP and SFTP connections are implemented in a variety of ways across different modules, which leads to code duplication and difficulties in maintenance. A unified approach will allow for easy management of file transfers, consistent error handling, and a more modular and extendable system.

Suggested implementation

Create a central class (or set of classes) that handles:

• FTP and SFTP connection establishment.
• File upload, download, and management.
• Error handling and logging.
• Support for additional features like SSH key authentication, passive mode, and more.

The classes should be designed to integrate seamlessly with existing Dolibarr modules, allowing easy adoption and reducing duplication of code for FTP/SFTP functionality.

Suggested steps

1. Analyze current FTP/SFTP implementations across Dolibarr to identify common functionalities and patterns.
2. Design a central class with reusable methods for connecting, uploading, downloading, and error handling.
3. Integrate the classes into the core system, ensuring backward compatibility with existing modules that require FTP/SFTP.
4. Write tests for various FTP/SFTP scenarios, including error handling and edge cases.
5. Update relevant documentation and examples for module developers to easily adopt the new connector classes.