Durgod keyboard refactor in preparation for adding additional durgod keyboards (#11978)

* Durgod keyboard refactor in preparation for adding additional durgod keyboards

* Moving Durgod board configuration into a common location
* Reformatting layout macro whitespace
* Moving TGUI key functionality to the keyboard level
* Replacing default keymap.c with keymap.json
* Changing default and default_toggle_mac_windows keymaps to LAYOUT_all
* Increasing EEPROM size to support more VIA layers
* Fixing media keys; KC_MRWD/KC_MFFD => KC_MPRV/KC_NXT

* Move ISO Enter key to the correct row in Durgod K320

* Minor whitespace and readme cleanup for K320

* Changing durgod/k320 debounce back to default

* Simplifying DURGOD_STM32_F070's chconf.h

Co-authored-by: Simon Arlott <sa.me.uk>
Co-authored-by: Tyler Tidman <tyler.tidman@draak.ca>

keyboards/durgod/k320/keymaps/kuenhlee/keymap.c

@@ -35,11 +35,6 @@
 #define KC_STOP LCTL(LSFT(KC_HOME))   // Select from Cursor to Home
 #define KC_SEND LCTL(LSFT(KC_END))    // Select from Cursor to End
 
-// Defines the keycodes used by our macros in process_record_user
-enum custom_keycodes {
-  KC_TGUI = SAFE_RANGE  // Toggle between GUI Lock or Unlock
-};
-
 // °±²³µ©ΩθΩ√∞∆≈≠→↓←↑≡■□●○∴«»÷≤≥Σ
 // Defines the Enumeration for Unicode Map
 enum unicode_names {