Improve the comparison of ScheduleExpression in TimerServiceImpl

TimerServiceImpl class currently contains the method that compares 2 ScheduleExpression values. Need to consider the following optimization:

• move this part from TimerServiceImpl to CalendarBasedTimeout, which is the class that handles calendar timer logics and already contains similar functionalities.
• make it a public static method
• the current comparison basically compares all ScheduleExpression attributes. We should order them to first compare attributes that are mostly likely to differ, with timezone, end, start at last.
• use Objects.equals instead of the custom same() method.