[Grbl_Esp32 PR#632] Big BUILD_INFO fix

— Changes that affect behavior

Fixed the bugs with reportbuildinfo()

Build info is no longer stored in the fixed “EEPROM” section; instead it
is a proper Setting named $Firmware/Build . You can change it in the
usual way with $Firmware/Build=

The #define ENABLEBUILDINFOWRITECOMMAND is gone. $I= is no longer supported,
$I without the = still works.

— Changes that affect configurability for developers

Converted a couple more #defines into enums – SETTINGSRESTORE*
and BITFLAGRTSTATUS_* . A side effect of this is that it is
no longer possible to configure the behavior of $RST=* by defining
SETTINGSRESTOREALL to include only a subset. I think it is
a bad idea from a customer support perspective to have the meaning
of this command be different for different builds.

Changed some of the #define ENABLE_ names to eliminate “EEPROM”

— Changes that are purely cosmetic

Clarified descriptions in Config.h, to eliminate spurious/incorrect mentions
of “EEPROM”

Eliminated all mentions of the name “EEPROM” except the ones
that truly mean the EEPROM section, as opposed to generalized
non-volatile storage.

The contents of SettingsStorage.h and SettingsStorage.cpp, which
were really related to coordinate storage in Eeprom, not proper
settings, were moved to Eeprom.h and Eeprom.cpp. The SettingsStorage
files are gone.

Got rid of getsteppinmask() and getdirectionpinmask() because
they were just aliases for bit(). That eliminated some junk from
the SettingsStorage/Eeprom files. Those files now tightly contain
only the residual stuff related to the storage of coordinate data
in EEPROM.