Fix deviation may not align with settings during runtime and Add CPU load balancer

[pin-chen]

Fix the issue of continuous VM migrations occurring.

• Deviation is halved during reading: Adjust the code so that deviation is not halved before use.
• Removal of the logic that lowers deviation after 10 consecutive migrations without movement, as deviation is randomly divided by 2, 4, 8 during the process, causing unexpected migration patterns.

Add CPU load balancer.

• Node switching does not occur automatically when there is CPU imbalance, leading to inefficiency issues.