[Aggregator Qt5] remove splitter position saving from destuctor
[Aggregator Qt5] delete aggregator widget on Release
[OverAll] define Q_PLUGIN_METADATA macros
[Aggregator Qt5] use Q_PLUGIN_METADATA without qt5 guards
[Aggregator BodyFetch Qt5] use Q_PLUGIN_METADATA without qt5 guards
[CSTP:wq Qt5] use Q_PLUGIN_METADATA without qt5 guards
[LHTR Qt5] use Q_PLUGIN_METADATA without qt5 guards