i18n: English/German from Switch system language

- Add I18n module: German when system language is DE, else English (ENUS/ENGB
  or any other language).
- Translate UI strings (tabs, settings, about, file browser, notifications,
  OC row titles, toggles Ein/Aus).
- Keep toggle/frequency/voltage list rows without subtitle descriptions
  like before.

Uses setGetSystemLanguage + setMakeLanguage; call I18n::init before
Application::init.

Made-with: Cursor

src/main.cpp

@@ -17,11 +17,14 @@
 #include "main_frame.h"
 #include "logo.h"
 #include "app_config.h"
+#include "i18n.h"
 
 int main(int argc, char* argv[])
 {
+    I18n::init();
+
     // Init the app
-    if (!brls::Application::init("SWR INI Tool"))
+    if (!brls::Application::init(I18n::appTitle()))
     {
         brls::Logger::error("Unable to init Borealis application");
         return EXIT_FAILURE;