Followup to #11994

* Clean up Temperature PID
* Improve EEPROM read/write/validate
* Group `SINGLENOZZLE` saved settings
* Group planner saved settings
* Group filament change saved settings
* Group skew saved settings
* Group `FWRETRACT` saved settings

Addressing #12048

Co-Authored-By: timoxd7 <timoxd7@users.noreply.github.com>

Previously, it was not possible for the TYPE argument to ultralcd menu macros to itself be a #defined value. This made it difficult to create variables to set many related menu items to a common precision that could be easily changed.

Also added details to the README to make sure the Ender-2 status is properly documented.

* Allow override of soft SPI pins in `pins_*.h`
* Add default case to avoid compiler warning.
* Additional pin definitions for Archim 2.
* Einsy Retro has same timings as Einsy Rambo.

…and change a multi-use "back" menu item.

* Don't react to s2g on TMC2660. False positives
* Init with sensorless probing as well

With default config and `EEPROM_SETTINGS`, saves over 200 bytes of PROGMEM.

Fix #12015

Fix #12004

Co-Authored-By: marcio-ao <marcio@alephobjects.com>

- Use a comma for decimals just in one message has not been a good idea.
- Full comments translation

Prescalers aren't calculated for the given target frequency.
Stepper timer should run at 2 Mhz and temperature timer at 72 Khz.