Map: in dive-site-edit mode, select those maps we filter for

When dive sites are edited, we shouldn't highlight the sites
of the current dive, but the currently edited site(s).

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

qt-models/filtermodels.h

@@ -64,6 +64,7 @@ public:
 	int divesDisplayed;
 	bool lessThan(const QModelIndex &, const QModelIndex &) const override;
 	bool diveSiteMode() const; // returns true if we're filtering on dive site
+	const QVector<dive_site *> &filteredDiveSites() const;
 public
 slots:
 	void myInvalidate();