JWST Mirror Actuators Refined

A refined version of JWST Mirror Actuators to make assembling easier.

Changes include but are not limited to:

1. Tolerance adjustment
2. Some parts split into multiple components to allow easier assembly
3. Add stoppers for bearings to prevent them from falling
4. Changed the shafts and gears to allow easier assembly and stronger connection
5. Change shaft designs for easier FDM printing.

Video showing the built: https://www.bilibili.com/video/BV1F24y127Nd/ (In Chinese)