Add ball joint cone constraints to specification

## Desired behavior

Add parameters to the specification for a cone constraint on ball joints, as this is supported by some physics engines, such as the [btConeTwistConstraint](https://github.com/bulletphysics/bullet3/blob/master/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h) in bullet.

## Alternatives considered

## Implementation suggestion

## Additional context