List and Map augmentations: count and exists

Lazy helpers:

    map_data():count(|key, item| -> item >=2)
    map_data():exists(|key, item| -> item ==2)
    map_data():exists(|key, item| -> item !=2)

    list_data():count(|item|->item>=2)
    list_data():exists(|item|->item==2) 
    list_data():exists(|item|->item>=10)