Joint limits Visualization for hinge and slider joints

**Is your feature request related to a problem? Please describe.**
Is there a method to visualize joint limits? It is rather tedious to see what I am adjusting especially when there are multiple complex joints in the XML.

**Describe the solution you'd like**
A way to visualize the joint angles using a `mjVIS_JOINT_LIMITS` Flag. Perhaps, with a calibration point for visualizing the joint limits.

**Additional context**
| Default calibration point | Offset of calibration by \theta|
|:---:|:---:|
| | |