Adjust functionality of time set commands

Currently, when a user types the command '/time set day' or 'time set night', the game will reset the absolute time of the world, meaning the 'Day' counter in the F3 menu gets reset to 0. Instead of resetting the absolute time, create a new method which would calculate the amount of ticks until daytime / nighttime and then add that amount of ticks onto the absolute time, hence preserving the actual day count of the world.