Make PREVENT_STUCK_MODIFIERS the default (#3107)

* Remove chording as it is not documented, not used, and needs work.

* Make Leader Key an optional feature.

* Switch from `PREVENT_STUCK_MODIFIERS` to `STRICT_LAYER_RELEASE`

* Remove `#define PREVENT_STUCK_MODIFIERS` from keymaps.

keyboards/ergodox_ez/config.h

@@ -97,8 +97,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #define DEBOUNCE    15
 
-#define PREVENT_STUCK_MODIFIERS
-
 #define USB_MAX_POWER_CONSUMPTION 500
 
 // RGB backlight

keyboards/ergodox_ez/keymaps/heartrobotninja/rules.mk

@@ -13,6 +13,7 @@ AUTOLOG_ENABLE = no
 RGBLIGHT_ENABLE = yes
 RGBLIGHT_ANIMATION = yes
 EXTRAKEY_ENABLE = yes
+LEADER_ENABLE = yes
 
 OPT_DEFS += -DUSER_PRINT
 
@@ -31,4 +32,4 @@ OPT_DEFS += -DKEYMAP_VERSION=\"$(KEYMAP_VERSION)\\\#$(KEYMAP_BRANCH)\"
 
 ifndef QUANTUM_DIR
 	include ../../../../Makefile
-endif
+endif

keyboards/ergodox_ez/keymaps/vim/vim.h

@@ -9,7 +9,6 @@
 
 #define PRESS(keycode) register_code16(keycode)
 #define RELEASE(keycode) unregister_code16(keycode)
-#define PREVENT_STUCK_MODIFIERS
 
 uint16_t VIM_QUEUE = KC_NO;