Tarmo5 Hexagonal gearbox mount

I've done the following modifications to:

• MAIN_GEAR_HUB(C06) to use a hexagonal shape and same dimension over length.
• CV_GEAR_HOUSING(C02) hexagonal shape and longer
• TORQUE_DAMPER(C05) made this a bit bigger so they can handle more torque
• CV_CAGE(C03) these are from other authors, they're the beefed up versions that can be printed in anything, and there is also a closed version that can be printed in TPU