feat: Implement fix for sunlight fading issue (#603)

## Summary

* **What is the goal of this PR?**

The goal of this PR is to deliver a fix for or at least mitigate the
impact of the issue described in #561

* **What changes are included?**

This PR includes a new option "Sunlight Fading Fix" under "Settings ->
Display".

When set to ON, we will disable the displays analog supply voltage after
every update and turn it back on before the next update.

## Additional Context

* Until now, I was only able to do limited testing because of limited
sunlight at my location, but the fix seems to be working. I'll also
attach a pre-built binary based on 0.16.0 (current master) with the fix
applied to the linked ticket, as building this fix is a bit annoying
because the submodule open-x4-sdk also needs an update.
* [PR in
open-x4-sdk](https://github.com/open-x4-epaper/community-sdk/pull/15)
needs to be merged first, we also need to add another commit to this
here PR, updating this dependency.
* I decided to hide this behind a default-OFF option. While I'm not
really concerned that this fix might potentially damage the display,
someone more knowledgeable on E-Ink technology could maybe have a look
at this.
* There's a binary attached in the linked issue, if someone has the
required sunlight to test this in-depth.

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _**NO**_

---------

Co-authored-by: Dave Allie <dave@daveallie.com>

lib/GfxRenderer/GfxRenderer.h

@@ -32,6 +32,7 @@ class GfxRenderer {
   HalDisplay& display;
   RenderMode renderMode;
   Orientation orientation;
+  bool fadingFix;
   uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
   std::map<int, EpdFontFamily> fontMap;
   void renderChar(const EpdFontFamily& fontFamily, uint32_t cp, int* x, const int* y, bool pixelState,
@@ -42,7 +43,8 @@ class GfxRenderer {
   void fillArc(int maxRadius, int cx, int cy, int xDir, int yDir, Color color) const;
 
  public:
-  explicit GfxRenderer(HalDisplay& halDisplay) : display(halDisplay), renderMode(BW), orientation(Portrait) {}
+  explicit GfxRenderer(HalDisplay& halDisplay)
+      : display(halDisplay), renderMode(BW), orientation(Portrait), fadingFix(false) {}
   ~GfxRenderer() { freeBwBufferChunks(); }
 
   static constexpr int VIEWABLE_MARGIN_TOP = 9;
@@ -57,6 +59,9 @@ class GfxRenderer {
   void setOrientation(const Orientation o) { orientation = o; }
   Orientation getOrientation() const { return orientation; }
 
+  // Fading fix control
+  void setFadingFix(const bool enabled) { fadingFix = enabled; }
+
   // Screen ops
   int getScreenWidth() const;
   int getScreenHeight() const;