Add a speed knob to the wipe tower.

[GurgenCD]

The default for wipe_tower_speed is 80mm/s which was hardcoded before. The perimeter and grid section of the wipe tower will also print at wipe_tower_speed. Though before it was hardcoded independently at 60mm/s.

wipe_tower_wipe_starting_speed is set to 26mm/s by default. And uses the same ramp up logic as before. Ramping up the speed of the wipe lines with an aggressive curve, before moving linearly 0.8mm/s at a time.

wipe_tower_wipe_starting_speed can be turned of by setting to 0.

The wipe_tower_speed is capped by the filament_max_volumetric_speed. If filament_max_volumetric_speed is not set (0 value), then there is no cap.

I personally only set a filament_max_volumetric_speed on stuff like very flexible TPU and what not. For the rest, I depend on the global volumetric speed limit. This way, I can set the wipe tower speed to exceed my normal printing flow rate since quality of the wipe tower doesn't matter. But a low flow rate filament would still be capped by filament_max_volumetric_speed, preventing a mess.

I have copied the code from https://github.com/prusa3d/PrusaSlicer/pull/9293 branch of Prusa Slicer, and changed the UI binding to align with how it's processed in SuperSlicer, as well as compiled and tested.