Refactor: optimize FlyByCamera and reduce object allocations + javadoc

[capdevon]

The main differences between the two versions of the FlyByCamera.java file are as follows:

• Copyright Update: The copyright year was updated from 2023 to 2025.
• Improved Documentation: Many Javadoc comments were rewritten for clarity, accuracy, and better parameter descriptions.
• Initialization and Memory Optimization: Temporary objects (matrices, vectors, quaternions) were added as reusable fields to reduce object allocations during camera updates, improving performance.
• Method Refactoring: Several methods (such as rotateCamera, riseCamera, and moveCamera) were refactored to use the new reusable temporary fields instead of creating new objects every time, resulting in more efficient and cleaner code.
• Input Handling Changes: In the onAction method, the boolean parameter was renamed for clarity, and usage was updated accordingly.
• Minor Logic Adjustments: Small changes were made to logic, such as adding checks to prevent near-zero field of view values in zoomCamera, and clarifying joystick mapping and input unregistration handling.

Overall, the updated file focuses on performance improvements, clearer documentation, and minor logic corrections, with no major functional changes to the camera’s behavior.

[richardTingle]

This section might be worth a second option (i.e. I'm not qualified to decide if this is a good change

        if (newFov > 0.01f) {
            cam.setFov(newFov);
        }

Otherwise I have reviewed and this looks good