Auto-recalculate shipping when the address changes

Right now people need to click "Recalculate shipping" at checkout when they change the address, to refresh the form.
That should be done automatically like in 1.x.

1) Hide the button.
This should do the trick:

  '#attributes' => [
      'class' => ['js-hide'],
  ],

2) When the address changes (no clue which JS event to use, check 1.x), check that the address is complete, and if it is, click the button.

Notes;
1) The address is complete if all of its required fields are filled.
2) Once the field is complete, we only need to recalculate if one of these fields changed: dependent_locality, locality, postal_code, administrative_area.
We don't care about the name, organization, address lines.