Expand vehicle variants

[Xenius97]

Summary

This PR expands the possibilities for vehicle variants, increasing the available base limit from 6 to 253.
(254 = random default variant, 255 = reset variants)
Extras are indexed starting from 1, so for example, extra40 will be variant 39.
By default, GTA:SA can handle extras from extra1 to extra5. With this update, modelers can now use extra6 through extra253, and MTA will handle these natively. These components should be added to chassis_dummy like other variants.

Motivation

Currently, vehicle variants are quite limited by default. We use many vehicles where multiple types of the same model are available as separate variants, but often the default 6 variants are not enough, forcing us to rely on custom element data. This solution is much more performance-oriented and, incidentally, can natively handle 253 extra components without scripts.
Furthermore, in our case, there is no need to rely on custom element data, as the built-in synchronization manages this automatically.

Test plan

Start the attached resource and run setVehicleVariant(vehicle, 99, 39)
replace.zip

Checklist

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