[FeatureRequest]: Add M915 parameters to object model

[owendare]

Is your feature request related to a problem? Please describe.

This feature would allow "auto calibration" of stall detection in prints

Describe the solution you propose.

I've been working on a couple of macros to see if a reported stall is a false positive or not.
https://forum.duet3d.com/post/338205
If a stall is reported it measures the distance from the reported stall position to the end stop.
If there's no difference (or less than the set threshold) it's a false positive (no layer shift would result)

It strikes me that if the current values of M915 were shown in the object model, it might be possible to "auto-calibrate" stall detection for prints.
Each time the macro shows a false positive we could increment the current M915 S parameter (and maybe H as well)

Describe alternatives you've considered

Only other option is manual trial and error testing

Provide any additional context or information.

No response