Radio Enhancements

This script adds several useful enhancements to the in-game radio system.

1. You can now change the radio volume in vehicles at any time without opening the menu.

Default keys:
- Left Shift + 4 quieter
- Left Shift + 6 louder

The keys can be changed in the menu settings.

2. The current radio volume is shown for a short time in the F1 menu and then disappears again.

3. If you leave a vehicle while a station is playing, you can continue to hear the radio up to a certain distance.

- after leaving the vehicle, the volume is reduced to 50% of the current value (can be changed)
- if you move away from the vehicle, the music becomes quieter and quieter (maximum distance can be changed)
- if you move closer again, the volume gradually increases
- the radio must be switched off manually in the vehicle to disable this function
- the radio state (on/off) is saved individually for each vehicle
- helpers switch the radio on by default - you can hear it when driving past :) (helper radio can be disabled / changed)
- a RadioEnhancements.xml file is created in the modSettings folder where you can change values

4. Multiplayer

- the script synchronizes the radio status (on/off) of your multiplayer vehicles
- if another player drives past you with the radio switched on, you will hear it too

What I unfortunately cannot change

- unfortunately it is not possible to save specific radio stations for individual vehicles
- all vehicles still use the same global preferred station
- in multiplayer you hear your own client-side selected station in another player's vehicle, not theirs