lazy load the database sizes only when needed by the server inspector.

pglab/serverinspector/DatabasesPage.h

@@ -12,7 +12,7 @@ class QSortFilterProxyModel;
 
 class DatabasesPage: public QSplitter {
 public:
-    explicit DatabasesPage(QWidget * parent = nullptr);
+    explicit DatabasesPage(std::shared_ptr<OpenDatabase> opendatabase, QWidget * parent = nullptr);
 
     void setCatalog(std::shared_ptr<PgDatabaseCatalog> cat);