SYSML21 — Torque vector quantity missing in ISQMechanics

Standard library `ISQMechanics.sysml` contains a declaration of torque as a scalar quantity to represent torque magnitude, but the related torque vector quantity is missing.

A torque vector quantity and associated coordinate frame should be added using the same pattern as for other vector quantities.

Note: This issue was flagged in "SysML v2 Release" Google Group at https://groups.google.com/g/sysml-v2-release/c/w7ZbFZ9d-e0/m/yTF8oyb6AwAJ .