ScreenRecorder: Add additional search paths

Adds a function FileUtils::usefullExtraSearchPaths() that returns
OS specific paths that often are not in PATH by default, but contain
useful apps we want to find.

Change-Id: Ideb7c45b241c69c9f2db8f75726bb63249000a5f
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/libs/utils/fileutils.h

@@ -85,6 +85,9 @@ public:
 
     static FilePathInfo filePathInfoFromTriple(const QString &infos, int modeBase);
 
+    //! Returns known paths like /opt/homebrew on macOS that might not be in PATH
+    static FilePaths usefulExtraSearchPaths();
+
 #ifdef QT_WIDGETS_LIB
     static void setDialogParentGetter(const std::function<QWidget *()> &getter);