dartsim: Support joint dynamics parameters on Ball joints

[azeey]

Desired behavior

Support for parameters such as damping on ball joints.

Alternatives considered

none

Implementation suggestion

Currently, none of the dynamics parameters are supported. The comment on https://github.com/gazebosim/gz-physics/blob/62ee52cf00c39b50eeea3570f79623afa2225fc8/dartsim/src/SDFFeatures.cc#L1120 indicates that this is because SDFormat doesn't support it and the following issues confirm that:

https://github.com/gazebosim/sdformat/issues/331 https://github.com/gazebosim/sdformat/issues/1250 https://github.com/gazebosim/sdformat/issues/860

However, maybe we can add an implementation where the parameters from the first <axis> are used for all the DOFs.

Additional context

none