Add showIf Option for Conditional Target Menu Display (One-Time Check, Not Per-Tick)

[L1iith]

This PR introduces a new showIf property for target options, allowing developers to conditionally display options in the target menu based on custom logic. Unlike canInteract, which is evaluated every tick, showIf is only checked when the menu is about to be shown, improving performance and enabling more flexible UI logic.

How it helps:

• Reduces unnecessary per-tick checks for options that only need to be conditionally shown at menu open.
• Allows for advanced UI logic, such as hiding options based on player state, permissions, or other one-time conditions.
• Maintains backward compatibility existing options work as before if showIf is not used.
• Simple to use: just add a showIf function to your option definition.

Example usage:

showIf = function(entity, distance, coords, name)
    return not IsPedInAnyVehicle(PlayerPedId(), false)
end

This addition gives developers more control over when options appear, without impacting runtime performance.