Change Command keycode defaults to match corresponding Bootmagic codes (#5078)

Change Command keycode defaults to match corresponding Bootmagic codes (#5078)

* Change Command keycode defaults to match corresponding Bootmagic codes

* Make alternate magic key keycodes consistent

* Reflect changes from previous commit in tmk_core/common/command.c

* Remove unnecessary MAGIC_KEY_* definitions from keymaps compatible with these changes

* Swap E and BSPACE for MAGIC_KEY_EEPROM

* Add MAGIC_KEY_EEPROM_CLEAR instead of MAGIC_KEY_EEPROM_ALT

* Remove BOOTMAGIC_ENABLE checks around EECONFIG stuff

* Update Command descriptions