desktop: add tab-widget for dive computer names

If we want to include dive computer names in the undo system,
there should be visual feedback on undo/redo.

This would mean opening the divecomputer dialog, which would
appear quite strange. Therefore, add a tab. This is not ideal,
but consistent with the dive site tab, which probably shouldn't
be there either. In the future, the UI needs some rethinking.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

qt-models/divecomputermodel.h

@@ -33,6 +33,7 @@ private:
 class DiveComputerSortedModel : public QSortFilterProxyModel {
 public:
 	using QSortFilterProxyModel::QSortFilterProxyModel;
+	void remove(const QModelIndex &index);
 private:
 	bool lessThan(const QModelIndex &i1, const QModelIndex &i2) const;
 };