feat: Added BmpViewer activity for viewing .bmp images in file browser (#887)

## Summary

* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)

Implements new feature for viewing .bmp files directly from the "Browse
Files" menu.

* **What changes are included?**

You can now view .bmp files when browsing. You can click the select
button to open the file, and then click back to close it and continue
browsing in the same location. Once open a file will display on the
screen with no additional options to interact outside of exiting with
the back button.

The attached video shows this feature in action:


https://github.com/user-attachments/assets/9659b6da-abf7-4458-b158-e11c248c8bef

## Additional Context

* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
  specific areas to focus on).

The changes implemented in #884 are also present here as this feature is
actually what led to me noticing this issue. I figured I would add that
PR as a separate request in case that one could be more easily merged
given this feature is significantly more complicated and will likely be
subject to more intense review.

---

### 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? **YES**

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/components/themes/lyra/LyraTheme.cpp

@@ -355,7 +355,7 @@ void LyraTheme::drawButtonHints(GfxRenderer& renderer, const char* btn1, const c
     const int x = buttonPositions[i];
     if (labels[i] != nullptr && labels[i][0] != '\0') {
       // Draw the filled background and border for a FULL-sized button
-      renderer.fillRect(x, pageHeight - buttonY, buttonWidth, buttonHeight, false);
+      renderer.fillRoundedRect(x, pageHeight - buttonY, buttonWidth, buttonHeight, cornerRadius, Color::White);
       renderer.drawRoundedRect(x, pageHeight - buttonY, buttonWidth, buttonHeight, 1, cornerRadius, true, true, false,
                                false, true);
       const int textWidth = renderer.getTextWidth(SMALL_FONT_ID, labels[i]);
@@ -363,7 +363,8 @@ void LyraTheme::drawButtonHints(GfxRenderer& renderer, const char* btn1, const c
       renderer.drawText(SMALL_FONT_ID, textX, pageHeight - buttonY + textYOffset, labels[i]);
     } else {
       // Draw the filled background and border for a SMALL-sized button
-      renderer.fillRect(x, pageHeight - smallButtonHeight, buttonWidth, smallButtonHeight, false);
+      renderer.fillRoundedRect(x, pageHeight - smallButtonHeight, buttonWidth, smallButtonHeight, cornerRadius,
+                               Color::White);
       renderer.drawRoundedRect(x, pageHeight - smallButtonHeight, buttonWidth, smallButtonHeight, 1, cornerRadius, true,
                                true, false, false, true);
     }