remove block enum

Replaced with dynamic casts.

app/node/block/gap/gap.cpp

@@ -31,11 +31,6 @@ Node *GapBlock::copy() const
   return new GapBlock();
 }
 
-Block::Type GapBlock::type() const
-{
-  return kGap;
-}
-
 QString GapBlock::Name() const
 {
   return tr("Gap");

app/node/block/gap/gap.h

@@ -38,8 +38,6 @@ public:
 
   virtual Node * copy() const override;
 
-  virtual Type type() const override;
-
   virtual QString Name() const override;
   virtual QString id() const override;
   virtual QString Description() const override;