refactor: Deduplicate Roundraff battery drawing (#1847)

## Summary

Deduplicated battery drawing code for Roundraff theme with other themes.

Now `BaseTheme` provides non-virtual `drawBatteryLeft` and
`drawBatteryRight` methods, which use a shared static
`drawBatteryOutline` implementation, and defer to a virtual
`fillBatteryIcon` implementation. In Classic and Roundraff
`fillBatteryIcon` uses a solid fill, while Lyra and Lyra Extended use a
segmented fill.

The charging indicator inside the battery was missing for Roundraff, but
is now consistent with other themes because of the shared drawing
implementation.

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src/components/themes/lyra/LyraTheme.h

@@ -49,9 +49,7 @@ constexpr ThemeMetrics values = {.batteryWidth = 16,
 class LyraTheme : public BaseTheme {
  public:
   // Component drawing methods
-  //   void drawProgressBar(const GfxRenderer& renderer, Rect rect, size_t current, size_t total) override;
-  void drawBatteryLeft(const GfxRenderer& renderer, Rect rect, bool showPercentage = true) const override;
-  void drawBatteryRight(const GfxRenderer& renderer, Rect rect, bool showPercentage = true) const override;
+  void fillBatteryIcon(const GfxRenderer& renderer, Rect rect, uint16_t percentage) const override;
   void drawHeader(const GfxRenderer& renderer, Rect rect, const char* title, const char* subtitle) const override;
   void drawSubHeader(const GfxRenderer& renderer, Rect rect, const char* label,
                      const char* rightLabel = nullptr) const override;