SCUMM: Use correct array size when calling initializeLocals()

The initializeLocals() function assumes that it can copy 25
elements when being provided an array of values. But this array
was frequently a lot smaller than that. I've introduced a constant
for the number of locals (though VirtualMachineState has one more
for some reason), and fixed the array sizes in a number of places.

CID 1003951, 1003952, 1003953, 1003955, 1003956, 1003959, 1003960,
1003961, 1003963, 100394, 1003965