pre-process gcode conditionals on the server#241

When printing objects of various heights, setting the auto-ejection macro by printer is impossible to optimize for Bambu printers, as they can’t use the SP slicer conditionals.

The bed needs to be positioned such that the top of the object clears the top of the door opening, but not so low as the print head misses the object. One way to do this would be to use Z{max_height]-65, but only where the object is >65mm tall. Otherwise, Z1 is fine. This could be done with an if/else conditional.

This could be solved, for all files/printers that don’t use the SP slicer by pre-processing the conditionals on the server before sending the gcode to the printer.