Allow the horn to interrupt the siren

[matsn0w]

Is your feature request related to a problem? Please describe.
In some countries, the horn interrupts the siren (mostly air horns). This is currently not possible (the horn plays through the siren).

Describe the solution you'd like
An option to allow the horn to interrupt the siren, probably on a per-vehicle basis.

Describe alternatives you've considered
A global option in config.lua, but that gives the user less flexibility.

Additional context
This feature is requested by @kadirgultekin via the Discord server