Utils: Introduce FilePath::displayName()

To produce "<filepath> on <devicename>" which is nicer to read than
"<scheme>://<deviceid>/<filepath>" in some places.

Change-Id: Ife47bbf49382cf73dd4709d826bdeaa8730f88be
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/utils/filepath.h

@@ -175,6 +175,7 @@ public:
     // on Windows and macOS. This is rarely needed.
     [[nodiscard]] FilePath normalizedPathName() const;
 
+    QString displayName(const QString &args = {}) const;
     QString nativePath() const;
     QString shortNativePath() const;
     bool startsWithDriveLetter() const;