Merge #477: Monospaced output in Console on macOS

b9f0aff qt: monospaced output in Console on macOS (randymcmillan)

Pull request description:

  This PR addresses issue #273
  A monospace font is used on Linux and Windows for the console output - but not on MacOS.
  This change forces the MacOS GUI to use the embedded RobotoMono-Bold.ttf font,
  which is defined as the GUIUtil::fixedPitchFont()

ACKs for top commit:
  hebasto:
    ACK b9f0aff, Tested on macOS Big Sur 11.6.1 (20G224) + Homebrew's Qt 5.15.2:
  shaavan:
    reACK b9f0aff
  jarolrod:
    tACK b9f0aff

Tree-SHA512: 53e6635a0189e133681c85d442c6c9c4a10438151e4bf7da5bbd62abca7ab55685caf2c9a75ff200aadea771c1602902e6ab14afdc4f411e1b3013dd49625dbc

Author: hebasto

src/qt/rpcconsole.cpp

@@ -866,7 +866,11 @@ void RPCConsole::clear(bool keep_prompt)
     }
 
     // Set default style sheet
+#ifdef Q_OS_MAC
+    QFontInfo fixedFontInfo(GUIUtil::fixedPitchFont(/*use_embedded_font=*/true));
+#else
     QFontInfo fixedFontInfo(GUIUtil::fixedPitchFont());
+#endif
     ui->messagesWidget->document()->setDefaultStyleSheet(
         QString(
                 "table { }"