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/TactilityHeadless.cpp

@@ -4,6 +4,9 @@
 #include "hal/Hal_i.h"
 #include "service/ServiceManifest.h"
 #include "service/ServiceRegistry.h"
+#include "kernel/SystemEvents.h"
+#include "network/NtpPrivate.h"
+#include "time/TimePrivate.h"
 
 #ifdef ESP_PLATFORM
 #include "EspInit.h"
@@ -39,7 +42,9 @@ void initHeadless(const hal::Configuration& config) {
     initEsp();
 #endif
     hardwareConfig = &config;
+    time::init();
     hal::init(config);
+    network::ntp::init();
     register_and_start_system_services();
 }