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

Platforms/platform-posix/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.20)
+
+file(GLOB_RECURSE SOURCES "source/*.c**")
+
+add_library(platform-posix OBJECT)
+target_sources(platform-posix PRIVATE ${SOURCES})
+#target_include_directories(platform-posix PUBLIC include/)
+target_link_libraries(platform-posix PUBLIC TactilityKernel)