Improve hall signal filtering

[at-wat]

Since the hall sensor has a relatively large delay which makes phase error in high-speed operation, tf-2md3 doesn't rely on the hall signal by default.
This strategy works well for mobile robot wheel as their velocity often crosses zero. However, it can cause accumulated phase error on continuously rotating motors.

• make it easy to set the velocity threshold to use/ignore hall signal
• estimate hall signal delay and compensate delay on high speed