Book cover sleep screen (#89)

## Summary

* Fix issue with 2-bit bmp rendering
* Add support generate book cover BMP from JPG and use as sleep screen

## Additional Context

* It does not support other image formats beyond JPG at this point
* Something is cooked with my JpegToBmpConverter logic, it generates
weird interlaced looking images for some JPGs

| Book 1 | Book 2|
| --- | --- |
|
![IMG_5653](https://github.com/user-attachments/assets/49bbaeaa-b171-44c7-a68d-14cbe42aef03)
|
![IMG_5652](https://github.com/user-attachments/assets/7db88d70-e09a-49b0-a9a0-4cc729b4ca0c)
|

src/CrossPointSettings.h

@@ -15,8 +15,11 @@ class CrossPointSettings {
   CrossPointSettings(const CrossPointSettings&) = delete;
   CrossPointSettings& operator=(const CrossPointSettings&) = delete;
 
+  // Should match with SettingsActivity text
+  enum SLEEP_SCREEN_MODE { DARK = 0, LIGHT = 1, CUSTOM = 2, COVER = 3 };
+
   // Sleep screen settings
-  uint8_t whiteSleepScreen = 0;
+  uint8_t sleepScreen = DARK;
   // Text rendering settings
   uint8_t extraParagraphSpacing = 1;
   // Duration of the power button press