Update to LVGL 9.0.0 (#47)

- Updated LVGL from 8.3 to 9.0 (removed example/docs/demo folders)
- Updated esp_lvgl_port  to current status of the `lvgl9` branch on `esp-bsp`: https://github.com/espressif/esp-bsp/tree/lvgl9
- Updated all boards and drivers
- Removed `libs/lv_drivers` subproject as SDL is now supported by LVGL directly (although keyboard input seems broken)
- Updated `libs/lv_screenshot`
- Fixed the way `tt_statusbar` widget works due to behaviour change in LVGL
- Updated other lvgl code

libs/esp_lvgl_port/idf_component.yml

@@ -0,0 +1,8 @@
+version: "1.5.0"
+description: ESP LVGL port
+url: https://github.com/espressif/esp-bsp/tree/master/components/esp_lvgl_port
+dependencies:
+  idf: ">=4.4"
+  lvgl/lvgl:
+    version: ">=8,<10"
+    public: true