Add Hotkeys to switch to 'previous' & 'next' utility tool

Currently the utility tools (umbrella, throwing knives, etc..) are bound to '8', '9', '0' which is fine but let's be honest in the heat of the battle if for example the bombs run out of durability it is kinda hard to press one of those buttons without having to focus all you attention on it. Thus 2 Hotkeys to switch to the 'next' / 'previous' utility tool would be a big help. Of course with a rollover where if your current tool is the '0' and you press 'next' tool '8' will be equipped.