refactor: Fixes for soft-off based on review.

* Better naming for gpio-key behavior triggers.
* Tweaks to scanned behavior trigger to avoid bad semaphore use,
  and reduce chance of issues with slowly scanned matrixes.
* Various code cleanups of style issues.

app/boards/shields/zmk_uno/Kconfig.defconfig

@@ -20,4 +20,7 @@ config ZMK_RGB_UNDERGLOW
     select WS2812_STRIP
     select SPI
 
+config ZMK_PM_SOFT_OFF
+    default y if BOARD_NRF52840DK_NRF52840
+
 endif

app/boards/shields/zmk_uno/boards/nrf52840dk_nrf52840.conf

@@ -1 +0,0 @@
-CONFIG_ZMK_PM_SOFT_OFF=y

app/boards/shields/zmk_uno/boards/nrf52840dk_nrf52840.overlay

@@ -43,7 +43,7 @@ encoder: &qdec0 {
     };
 
     wakeup_source: wakeup_source {
-        compatible = "zmk,wakeup-trigger-key";
+        compatible = "zmk,gpio-key-wakeup-trigger";
         status = "okay";
 
         trigger = <&button0>;
@@ -58,7 +58,7 @@ encoder: &qdec0 {
     };
 
     soft_off_behavior_key {
-        compatible = "zmk,behavior-key";
+        compatible = "zmk,gpio-key-behavior-trigger";
         status = "okay";
         bindings = <&soft_off>;
         key = <&button0>;