Time & date, system events and much more (#152)

## Time & Date
- Added time to statusbar widget
- Added Time & Date Settings app
- Added TimeZone app for selecting TimeZone
- Added `tt::time` namespace with timezone code

## Other changes

- Added `SystemEvent` to publish/subscribe to system wide (e.g. for init code, but also for time settings changes)
- Changed the way the statusbar widget works: now there's only 1 that gets shown/hidden, instead of 1 instance per app instance.
- Moved `lowercase()` function to new namespace: `tt::string`
- Increased T-Deck flash & PSRAM SPI frequencies to 120 MHz (from 80 MHz)
- Temporary work-around (+ TODO item) for LVGL stack size (issue with WiFi app)
- Suppress T-Deck keystroke debugging to debug level (privacy issue)
- Improved SDL dependency wiring in various `CMakeLists.txt`
- `Loader` service had some variables renamed to the newer C++ style (from previous C style)

TactilityHeadless/Source/hal/Hal.cpp

@@ -1,16 +1,21 @@
 #include "hal/Hal_i.h"
 #include "hal/i2c/I2c.h"
+#include "kernel/SystemEvents.h"
 
 #define TAG "hal"
 
 namespace tt::hal {
 
 void init(const Configuration& configuration) {
+    kernel::systemEventPublish(kernel::SystemEvent::BootInitHalBegin);
+
+    kernel::systemEventPublish(kernel::SystemEvent::BootInitI2cBegin);
     tt_check(i2c::init(configuration.i2c), "I2C init failed");
     if (configuration.initHardware != nullptr) {
         TT_LOG_I(TAG, "Init hardware");
         tt_check(configuration.initHardware(), "Hardware init failed");
     }
+    kernel::systemEventPublish(kernel::SystemEvent::BootInitI2cEnd);
 
     if (configuration.initBoot != nullptr) {
         TT_LOG_I(TAG, "Init power");
@@ -23,6 +28,8 @@ void init(const Configuration& configuration) {
             TT_LOG_W(TAG, "SD card mount failed (init can continue)");
         }
     }
+
+    kernel::systemEventPublish(kernel::SystemEvent::BootInitHalEnd);
 }
 
 } // namespace