Show a summary of the partition changes on the summary page

src/libcalamaresui/viewpages/ViewStep.cpp

src/libcalamaresui/viewpages/ViewStep.h

src/modules/partition/PartitionCoreModule.cpp

src/modules/partition/PartitionCoreModule.h

src/modules/partition/PartitionViewStep.cpp

src/modules/partition/PartitionViewStep.h

src/modules/summary/SummaryPage.cpp

src/modules/summary/SummaryPage.h