Brings back the current Z display in the state sidebar panel

OctoPrint’s state sidebar display panel used to display the current Z height of the printer’s nozzle.

That information is sadly inaccurate - it stems not from actual position information from the printer’s firmware but instead from an attempt at tracking the height information by OctoPrint, which can lag behind, be inaccurate or not work at all in case of prints from SD cards.

However, people demanded to get this piece of information back, inaccurate or not, so here it is as plugin.

Pictures

Screenshot of DisplayZ plugin