Added a ModelSummary class to make the overview over the model content accessible via QProperty system & a SummaryWidget to show this information. Only property rowCount as a proof of concept. Other properties will follow.

libs/BeetRoundCore/CMakeLists.txt

@@ -32,6 +32,7 @@ add_library(${TARGET_APP} STATIC
   model/tablemodel.h model/tablemodel.cpp
   model/modelitem.h model/modelitem.cpp
   model/generalsortfiltermodel.h model/generalsortfiltermodel.cpp
+  model/modelsummary.h model/modelsummary.cpp
   model/commands/insertrowscommand.h model/commands/insertrowscommand.cpp
   model/commands/removerowscommand.h model/commands/removerowscommand.cpp
   model/commands/edititemcommand.h model/commands/edititemcommand.cpp