Implement UI scaling and more (#501)

**New Features**
 * Runtime font accessors and new symbol fonts for text, launcher, statusbar, and shared icons.
 * Added font height base setting to device.properties
 * Text fonts now have 3 sizes: small, default, large

**Improvements**
 * Renamed `UiScale` to `UiDensity`
 * Statusbar, toolbar and many UI components now compute heights and spacing from fonts/density.
 * SSD1306 initialization sequence refined for more stable startup.
 * Multiple image assets replaced by symbol-font rendering.
 * Many layout improvements related to density, font scaling and icon scaling
 * Updated folder name capitalization for newer style

Tactility/Source/app/settings/Settings.cpp

@@ -23,7 +23,7 @@ static void createWidget(const std::shared_ptr<AppManifest>& manifest, void* par
     const void* icon = !manifest->appIcon.empty() ? manifest->appIcon.c_str() : LVGL_SYMBOL_TOOLBAR;
     auto* btn = lv_list_add_button(list, icon, manifest->appName.c_str());
     lv_obj_t* image = lv_obj_get_child(btn, 0);
-    lv_obj_set_style_text_font(image, LVGL_SYMBOL_FONT_DEFAULT, LV_PART_MAIN);
+    lv_obj_set_style_text_font(image, lvgl_get_shared_icon_font(), LV_PART_MAIN);
     lv_obj_add_event_cb(btn, &onAppPressed, LV_EVENT_SHORT_CLICKED, (void*)manifest.get());
 }