Description

This PR refactors the ESX inventory system to:

• Replace context menus with default menus for better UX.
• Restructure the inventory logic into modular helper functions for improved maintainability and readability.
• Separate the inventory into its own dedicated resource, making it easier to update, manage, and customize.

Motivation

The previous implementation relied heavily on context menus with inline logic, making it harder to maintain and extend.
By moving to esx_menu_default and extracting menu building into helper functions, we:

• Improve readability by reducing inline complexity.
• Allow future enhancements (sorting, filtering, item categorization) without touching core ESX files.
• Make it easier for server owners to customize their inventory system.

PR Checklist

• My commit messages and PR title follow the Conventional Commits standard.
• My changes have been tested locally and function as expected.
• My PR does not introduce any breaking changes.
• I have provided a clear explanation of what my PR does, including the reasoning behind the changes and any relevant context.