Added: Filter for plugin archives

Quote from i-MSCP Github (1.5.3)

Code

1. Added: Filter for plugin archives
2. Added: Validator for plugin archives
3. Removed: iMSCP_Plugin base class (replaced by iMSCP_Plugin_Action class)
4. Review: Plugin manager
5. Review: Plugin UI
6. CS fixes +++

Source: https://github.com/i-MSCP/imsc…1e57740b59cdfa4457c3c9eb8