Utils: Introduce PathChoser::absoluteFilePath()

As we have a valid context to resolve relative files here
this is a good source for absolute files that don't depend
on QFilePath::absolute{File,}Path or similar.

Change-Id: Iaf592aa746023f80de517703e32e6b80a3d0fd7e
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Artem Sokolovskii <artem.sokolovskii@qt.io>

src/libs/utils/pathchooser.cpp

@@ -357,6 +357,11 @@ FilePath PathChooser::filePath() const
     return d->expandedPath(rawFilePath().toString());
 }
 
+FilePath PathChooser::absoluteFilePath() const
+{
+    return d->m_baseDirectory.resolvePath(filePath());
+}
+
 // FIXME: try to remove again
 QString PathChooser::expandedDirectory(const QString &input, const Environment &env,
                                        const QString &baseDir)