DolphinQt: Size adjustments in **Breakpoints** widget based on selected debug font.

- Debug font is now used in the widget.
- Row height is now determined by the character height of the current
  font.
- A `OnDebugFontChanged()` slot has been connected to properly update
  the widget on debug font changes.

| Before | After |
| --- | --- |
| <img alt="Breakpoints widget (before)" title="Breakpoints widget (before)" src="https://github.com/user-attachments/assets/fdde293a-b1fd-4a1d-85e2-e16bc859eb9e" /> | <img alt="Breakpoints widget (after)" title="Breakpoints widget (after)" src="https://github.com/user-attachments/assets/cf4f1d59-c235-429b-bcb1-cae36065e805" /> |

Source/Core/DolphinQt/Debugger/BreakpointWidget.h

@@ -65,6 +65,8 @@ private:
   void OnSave();
   void OnContextMenu(const QPoint& pos);
   void OnItemChanged(QTableWidgetItem* item);
+  void OnDebugFontChanged(const QFont& font);
+
   void UpdateIcons();
 
   Core::System& m_system;