Migration of ZString, ZArray, ZObject to EBox

[jmjoy]

This pull request introduces significant refactoring across multiple components of the codebase to enhance memory management, improve type safety, and simplify the implementation of core structures. Key changes include transitioning to the EBox smart pointer for memory management, streamlining object and array handling, and updating type conversions for better compatibility with the Zend Engine.

Memory Management Improvements:

• Introduced EBox<T> in phper/src/alloc.rs as a smart pointer for PHP values allocated in Zend Engine memory, replacing manual memory management. It handles deallocation automatically and provides safe access to PHP resources.
• Updated ZObject and StateObject<T> in phper/src/objects.rs to use EBox<T> for memory management, simplifying their implementation and ensuring proper cleanup. [1] [2]

Array Handling Enhancements:

• Refactored ZArray in phper/src/arrays.rs to use EBox<ZArr> for memory management, replacing manual pointer handling and improving safety. [1] [2]
• Added a Drop implementation for ZArr to ensure proper memory cleanup when arrays are destroyed.

Type Conversion Updates:

• Standardized pointer casting for type conversions across the codebase to ensure compatibility with Zend Engine APIs. Examples include updates in phper/src/classes.rs, phper/src/functions.rs, and phper/src/objects.rs. [1] [2] [3]

Test Improvements:

• Added an assertion to verify HTTP response status codes in integration tests for the HTTP server.

Documentation and Cleanup:

• Removed outdated ebox! macro and associated EBox implementation from phper-alloc/src/lib.rs and phper-alloc/src/macros.rs. These have been replaced with the new EBox implementation in phper/src/alloc.rs. [1] [2]
• Updated documentation for ZObject and StateObject<T> to reflect their new implementations using EBox. [1] [2]