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-esp32/bindings/espressif,esp32-uart.yaml

@@ -0,0 +1,29 @@
+description: ESP32 UART Controller
+
+include: ["uart-controller.yaml"]
+
+compatible: "espressif,esp32-uart"
+
+properties:
+  port:
+    type: int
+    required: true
+    description: |
+      The port number, defined by uart_port_t.
+      Depending on the hardware, these values are available: UART_NUM_0, UART_NUM_1, UART_NUM_2
+  pin-tx:
+    type: phandle-array
+    required: true
+    description: TX pin
+  pin-rx:
+    type: phandle-array
+    required: true
+    description: RX pin
+  pin-cts:
+    type: phandle-array
+    default: GPIO_PIN_SPEC_NONE
+    description: CTS pin
+  pin-rts:
+    type: phandle-array
+    default: GPIO_PIN_SPEC_NONE
+    description: RTS pin