ProjectExplorer: De-virtualize some more virtual methods

Use setters/getters for the bool flags in
Project::needsBuildConfigurations() and
Project::hasMakeInstallEquivalent.

Change-Id: I5ce937c3a5e8e0db627cda02a9007f8c28ccda0c
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmlprojectmanager/qmlproject.h

@@ -75,8 +75,6 @@ public:
 
     void refreshProjectFile();
 
-    bool needsBuildConfigurations() const final;
-
     static QStringList makeAbsolute(const Utils::FilePath &path, const QStringList &relativePaths);
 
     QVariant additionalData(Core::Id id, const ProjectExplorer::Target *target) const override;