ProjectExplorer: Streamline access to buildDirectoryTemplate data

There's only one kind of use, in the context of BuildConfiguration.

Change-Id: I09628ff443ef08e28738125a614c17d5d979189b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/buildconfiguration.h

@@ -110,6 +110,15 @@ public:
 
     static QString buildTypeName(BuildType type);
 
+    enum SpaceHandling { KeepSpace, ReplaceSpaces };
+    static Utils::FilePath buildDirectoryFromTemplate(const Utils::FilePath &projectDir,
+                                                      const Utils::FilePath &mainFilePath,
+                                                      const QString &projectName,
+                                                      const Kit *kit,
+                                                      const QString &bcName,
+                                                      BuildType buildType,
+                                                      SpaceHandling spaceHandling = ReplaceSpaces);
+
     bool isActive() const;
 
     void updateCacheAndEmitEnvironmentChanged();