Start develop VirtualListView

Due to Gtk don't support a virtual ListView, begin here developing an own virtual list view supporting all the needed features
to view a huge known list without accessing all values.
Access to content is on request and only for displayed rows.
VirtualListView consider scroll events
VirtualListView add block selection
VirtualListView programmatically columns
Disable designer icon for some widgets
VirtualListView make some functions public ready to use.