If Marlin is blocking the serial input or command queue for any length
of time (for example more than 2 seconds), it needs to send a message
to serial out to inform the host that it is busy. Marlin should only
send these messages out when busy, and preferably not when trying to
print formatted output.

follow-up the commit d56c6af24e

follow-up the commit 7326d63ce0
update Configration_adv.h of Hephestos2
delete unnecessary spaces

rebased
corrected spelling
changed to #elif for error

Still with MIN_Z_HEIGHT_FOR_HOMING but con be done with (folder wide) search-replace when we have a better name.

update old comments
update or delete deprecated definitions
complement forgotten updates
adjust spacing
some cosmetic changes

As suggested by @max-pau in #3073 - #3074

files.

Disallowed the Z_PROBE_OFFSET_RANGE_MAX to be greater than zero.

 - Remove the forced activation of SDSUPPORT, I guess people may use the ZUM
3D board and not the LCD module.
 - Fixed the tab issue within boards.h file.

Added support for BQ ZUM Mega 3D board and stock Hephestos 2 thermistor.

Redo of #2939 rebased against RCBugFix

Renamed `WARN_REDUCED_ACCURACY` to `DISABLE_REDUCED_ACCURACY_WARNING`

Changed the condition for blinking from
```
#if ENABLED(WARN_REDUCED_ACCURACY)
```
to
```
#if DISABLED(DISABLE_REDUCED_ACCURACY_WARNING)
```

* Configuration.h:
  * updated header comment
  * new UUID feature used
  * sync to default config
  * typos fixed
  * changes better documented
  * reflect change in SDSUPPORT feature
* Configuration_adv.h
  * updated header comment
  * thermal protection tuned to work with K8200
  * homing tuned
  * sync to default config
  * typos fixed
  * changes better documented
  * reflect change in LCD features
  * use long filenames
  * use Watchdog
  * use Babystepping
  * use Auto Filament Change

This formalizes the dependency of MANUAL_BED_LEVELING on
MESH_BED_LEVELING

- Include aligned comment about new SDSUPPORT behavior

Instead of changing SDEXTRASLOW variable to a slower speed,  the new
SDULTRASLOW is used for rigidbot panel.