[partition] Use Q_EMIT

src/modules/partition/core/Config.cpp

src/modules/partition/core/DeviceModel.cpp

src/modules/partition/core/PartitionCoreModule.cpp

src/modules/partition/core/PartitionModel.cpp

src/modules/partition/core/PartitionModel.h

src/modules/partition/gui/ChoicePage.cpp

src/modules/partition/gui/EncryptWidget.cpp

src/modules/partition/gui/PartitionSplitterWidget.cpp

src/modules/partition/gui/PartitionViewStep.cpp

src/modules/partition/gui/ReplaceWidget.cpp

src/modules/partition/gui/ScanningDialog.cpp

src/modules/partition/jobs/PartitionJob.cpp