createNewModelOnInsert property Null safety
When set to true a new ViewModel will be constructed everytime the widget is inserted.
When setting this to true make sure to handle all disposing of streams if subscribed
to any in the ViewModel.
onModelReady will fire once the ViewModel has been created/set.
This will be used when on re-insert of the widget the ViewModel has to be constructed with
a new value.
bool get createNewModelOnInsert => false;