[FeatureRequest]: Add M207 retraction parameters to OM Browser

[droftarts]

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

See forum thread: https://forum.duet3d.com/topic/36553/no-retraction-parameters-in-om
M207: https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m207-set-retract-length

Describe the solution you propose.

Add retraction parameters to OM browser in DWC.

Edit: It appears retraction settings are in the OM, but are not shown in the OM browser in DWC, at least not in DWC 3.5.2.

[chrishamm]

Fixed upstream in v3.5-dev and v3.6-dev.