Charged Weapon System

Hero has booleans to keep track of the current weapon and the current
charge weapon. Once weapon swapping is added, this system should allow
the user to fire a regular shot of whatever weapon is currently
equipped, and if the charged version of that shot is unlocked, be able
to charge the shot up. If the charged version is not unlocked, charging
is simply unavailable as long as that weapon is equipped. Swapping will
need to clear the current charge once implemented.