- create sled pin definition
- G28 Works with sled

to avoid errors in Marlin_main.cpp. #1860

In the include tree of Marlin_main.cpp the decision between the display types is not made.
To include the right LCD_STR_* ether 'dogm_lcd_implementation.h' or 'ultralcd_implementation_hitachi_HD44780.h' with all their code.
A 'dogm_lcd_implementation.h.h' would be a curiosity.
So i moved both of the definition blocks to conditionals.h

On the long term it could make sense to use the same numbering for the u8glib and the hitachi symbols.

and cleaned typo.

The other two devices we use in u8glib have more than only dummy code.
Checked this in the library code.

- Include the current Z when raising the axis after and between probing
- Add `sync_plan_position_delta` for parity with `sync_plan_position`
- Clean up and clarify `M48`, `dock_sled`, and others

and use them in temperuture.h

Flattened the if structure - the preprocessor is doing the work - not the Arduino. Arduino.

Documented some additional areas that should be addressed if Z_PROBE is
fully separated from Z_MIN or Z_MAX.
Fixed a documentation error in sanity checks. Servos start at 0 not 1.

make it unconditional
remove all definitions in the 'Configuration.h's
remove form 'Conditionals.h'

- `Conditionals.h` is included twice, setting LCD values the first time

- Add `Conditionals.h` with calculated configuration values
- Add `SanityCheck.h` with checks for configuration errors
- Remove equivalent code from all configurations
- Move error checks from some sources to `SanityCheck.h` also
- Fix initialization of count_direction in stepper.cpp