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/planck/keymaps/jarred/config.h

@@ -19,8 +19,6 @@
 
 #include "config_common.h"
 
-#define PREVENT_STUCK_MODIFIERS
-
 #ifdef AUDIO_ENABLE
     #define STARTUP_SONG SONG(PLANCK_SOUND)
 #endif
@@ -34,6 +32,6 @@
 
 #define MOUSEKEY_WHEEL_DELAY 0
 #define MOUSEKEY_WHEEL_MAX_SPEED   4
-#define MOUSEKEY_WHEEL_TIME_TO_MAX 255	
+#define MOUSEKEY_WHEEL_TIME_TO_MAX 255
 
 #endif