Testing: split input test (#2762)

test(pointing): Add mock input device.

New mock input device to generate input events for tests.

test(split): Add peripheral input test.

Test event propagation from peripheral input devices.

fix(split): Proper scoping for local within switch.

Minor compile fix.

chore: Fix up test snapshots after logging changes.

Adjust the test snapshots after logging changes to the central.

fix(kscan): Don't fire last mock event twice.

Fix a bug where the kscan mock would raise the last mock event
twice before halting processing.

app/tests/ble/split/peripheral-input/nrf52_bsim.keymap

@@ -0,0 +1,27 @@
+#include <behaviors.dtsi>
+#include <dt-bindings/zmk/bt.h>
+#include <dt-bindings/zmk/keys.h>
+
+#include "shared.dtsi"
+
+&kscan {
+    /delete-property/ exit-after;
+    events = <>;
+};
+
+&split_listener {
+    status = "okay";
+};
+/ {
+    keymap {
+        compatible = "zmk,keymap";
+
+        default_layer {
+            bindings = <
+            &kp A &kp B
+            &bt BT_SEL 0 &bt BT_CLR>;
+
+            sensor-bindings = <&inc_dec_kp A B>;
+        };
+    };
+};