add code action to update existing import statements.

[heejaechang]

add code action that let users to update import statement.

from module import A, B

A()
B()

to

import module

module.A()
module.A()

also, if possible, let pylance to find good abbr for module and also suggest that will convert the code to

import module as m

m.A()
m.B()

that also understand well known abbr such as np, pd and etc.

...

also, if possible, add new option such as always use 'import' statement instead of 'from xxx import' and add/auto import always add import statement with module.A form.