PFW-1561 Fix MMU unload issue

[3d-gussner]

The Tune menu is now also available during a fan error, so the user can decide to en/disable the fan check.
Send //action:cancel to host when Stop print is executed.

Steps to reproduce:

• Check Settings -> Fan check [On]
• Start MMU print
• While printing stall the hotend fan until the printer has finished pausing the print job.
• You can stop halting the fan now.
• Now, sit back and wait until the extruder temperature is below EXTRUDER_AUTO_FAN_TEMPERATURE (50°C). This can take ~10 minutes.
• Stop the print job via LCD menu

Results:

1. If fan is spinning the printer will heat up to target temperature and unload the filament from the MMU
2. If fan is still blocked ther printer will try to heat up but again fail with a fan error. A second Stop print is needed.

The preferred state of printer + MMU is to have no filament loaded after a print finished or has been stopped.
Advantages:

• Printer and MMU can reset and home after a startup.
• Next MMU print doesn't need an extra unload or purge sequence
• Switching MMU filament doesn't need an extra unload or purge sequence

Replaces #4771

ToDo

• Create cherry-pick PR to MK3_3.14.1 branch

[github-actions]

All values in bytes. Δ Delta to base

Target	ΔFlash	ΔSRAM	Used Flash	Used SRAM	Free Flash	Free SRAM
MK3S_MULTILANG	8	0	248044	5654	5908	2538
MK3_MULTILANG	8	0	247420	5663	6532	2529

[gudnimg]

If fan is still blocked ther printer will try to heat up but again fail with a fan error. A second Stop print is needed.

Tested this and works as described. Personally I don't like it, if the user wants to stop the print, it should stop the print. Not a good user experience having to click the "stop print" button twice.

[gudnimg]

If fan is still blocked ther printer will try to heat up but again fail with a fan error. A second Stop print is needed.

Tested this and works as described. Personally I don't like it, if the user wants to stop the print, it should stop the print. Not a good user experience having to click the "stop print" button twice.

I wonder if this works well. We do this when resuming a print. If the self test fails, we shouldn't bother or even try heating up the extruder.