Add ProcessMoveEvent, which is analagous to ThreadMoveEvent but operates on the
seec::cm::ProcessState. Add placeholder methods for moveToAllocation() and
moveToDeallocation() which will move a state, given a Value, to the Value's
initial allocation or eventual deallocation, if they exist, otherwise to the
start or end of the trace respectively. Modify the context menu used in the
state graph viewer when clicking on a Value to have two options which call these
movement methods.