Replace Tactility SystemEvents with new kernel implementation (#598)

TactilityKernel now has a system event API to replace the one from the Tactility subproject. It also implements several tests for it.

Devices/lilygo-tlora-pager/source/module.cpp

@@ -1,7 +1,8 @@
 #include <lvgl/lvgl.h>
 #include <tactility/module.h>
 
-#include <Tactility/SystemEvents.h>
+#include <tactility/system_event.h>
+
 #include <Tactility/kernel/Kernel.h>
 
 #include <lilygo/drivers/tpager_encoder_input.h>
@@ -10,22 +11,21 @@ constexpr auto* TAG = "T-Lora Pager";
 
 extern "C" {
 
-tt::kernel::SystemEventSubscription event_subscription = tt::kernel::NoSystemEventSubscription;
+static void on_boot_completed(struct SystemEvent* /*event*/, void* /*context*/) {
+    // The kernel tpager_encoder device is already started by kernel_init(); this just
+    // registers it as an LVGL input device, which requires LVGL to be up first.
+    lvgl_lock();
+    tpager_encoder::init();
+    lvgl_unlock();
+}
 
 static error_t start() {
-    event_subscription = tt::kernel::subscribeSystemEvent(tt::kernel::SystemEvent::BootSplash, [](tt::kernel::SystemEvent) {
-        // The kernel tpager_encoder device is already started by kernel_init(); this just
-        // registers it as an LVGL input device, which requires LVGL to be up first.
-        lvgl_lock();
-        tpager_encoder::init();
-        lvgl_unlock();
-    });
+    system_event_subscribe(KERNEL_EVENT_BOOT_COMPLETED, on_boot_completed, nullptr);
     return ERROR_NONE;
 }
 
 static error_t stop() {
-    tt::kernel::unsubscribeSystemEvent(event_subscription);
-    event_subscription = tt::kernel::NoSystemEventSubscription;
+    system_event_unsubscribe(KERNEL_EVENT_BOOT_COMPLETED, on_boot_completed);
     return ERROR_NONE;
 }