Nemeth Designs/FS24 Eurocopter EC-135 fuel usage fix

This add-on addresses a fuel transfer issue with the default Eurocopter EC-135T in FS24, ensuring that fuel is correctly managed from the main tank to the feeder tanks. By rewriting sections of the helicopters fuel system, it prevents engine stoppage during flight as the feeder tanks remain filled. Additionally, the mod enables the default handbrake, which is beneficial for compatibility with simulation extensions like FSEconomy. Users should note that the bug is resolved in SU4 and are advised to remove the mod if using the SU4 beta or after its release.