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/compilationdatabaseprojectmanager/compilationdatabaseproject.h

@@ -58,7 +58,6 @@ public:
     explicit CompilationDatabaseProject(const Utils::FilePath &filename);
     ~CompilationDatabaseProject() override;
     bool needsConfiguration() const override { return false; }
-    bool needsBuildConfigurations() const override { return true; }
 
 private:
     RestoreResult fromMap(const QVariantMap &map, QString *errorMessage) override;