improve customer display function (see details in description)

I think show all the information in main frame looks so messy, so, i add
a function that can choose what kind of information you want see in main
frame. But the program also hold all information from the database,
which will used to let user can see all information and edit information
in a new window. I will try to finish the edit function at first,
because about the remove function, i have some question about that, so,
we can discuss about that later