Move police job custom props to separate esx_custom_props resource

[subhampro]

Description

This PR moves custom props (handcuffs) from the esx_policejob resource to a new centralized esx_custom_props resource. This creates a dedicated resource for managing all custom props across ESX resources.

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Motivation

• Centralizes custom prop management to avoid conflicts between resources
• Provides a single location for all custom props used across ESX resources
• Improves modularity and maintainability of the codebase
• Prevents duplicate prop files across multiple resources

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Implementation Details

• Created new esx_custom_props resource with proper structure
• Moved handcuffs.ydr and handcuffs.ytyp from esx_policejob/stream/ to esx_custom_props/stream/
• Updated esx_policejob fxmanifest to depend on esx_custom_props
• Removed custom prop entries from esx_policejob manifest
• Added comprehensive documentation for future prop additions

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Usage Example

-- In any resource that needs custom props, add dependency:
dependencies {
    'esx_custom_props'
}

-- Props are automatically loaded and available in-game
-- No additional code changes needed for existing functionality

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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.

[N0tNvll]

I already tested and all good

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