Allow homing using original G28 when homing_override is present

This is sort of a feature request, but more than anything, I just want to see if other people would be interested in this (or if there are reasons this hasn’t been implemented).

I have a use case where, generally, I want to have ahoming_override for my z-axis. However, sometimes, I want to be able to use the original G28 homing command outside of the homing_override G-Code. This is similar to [gcode_macro] blocks which have a rename_existing parameter, allowing the use of the original gcode when neccessary.

Is there interest from others in having a rename_existing parameter on the [homing_override] block? If so, I’m more than happy to implement this!

I’ve now implemented this, and created a pull request (#6996).