- Addressing issue mentioned at #1699

Don’t set CUSTOM_M_CODE_SET_Z_PROBE_OFFSET if there’s no Z probe

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