feat(core): Adding pre-release for keys that were already pressed.

This fixes zmkfirmware#1207 and zmkfirmware#1076 (and maybe more?).

app/src/hid_listener.c

@@ -19,6 +19,20 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 static int hid_listener_keycode_pressed(const struct zmk_keycode_state_changed *ev) {
     int err, explicit_mods_changed, implicit_mods_changed;
 
+    if (zmk_hid_is_pressed(ZMK_HID_USAGE(ev->usage_page, ev->keycode))) {
+        LOG_DBG("unregistering usage_page 0x%02X keycode 0x%02X since it was already pressed",
+                ev->usage_page, ev->keycode);
+        err = zmk_hid_release(ZMK_HID_USAGE(ev->usage_page, ev->keycode));
+        if (err < 0) {
+            LOG_DBG("Unable to pre-release keycode");
+            return err;
+        }
+        err = zmk_endpoints_send_report(ev->usage_page);
+        if (err < 0) {
+            LOG_ERR("Failed to send key report for pre-releasing keycode", err);
+        }
+    }
+
     LOG_DBG("usage_page 0x%02X keycode 0x%02X implicit_mods 0x%02X explicit_mods 0x%02X",
             ev->usage_page, ev->keycode, ev->implicit_modifiers, ev->explicit_modifiers);
     err = zmk_hid_press(ZMK_HID_USAGE(ev->usage_page, ev->keycode));