Enterprise fee calculator: Allow to enter calculator settings immediately (without saving/reloading the page first)

[drummer83]

Description

- As a: enterprise user or super admin - On page: /admin/enterprise_fees - I want to be able to do: currently you need to save to see the calculator fields, the idea here is to removing that additional saving step:

1. Enter information and select the calculator (the UI automatically shows the relevant fields for that calculator)
2. Enter the calculator settings
3. Save the page just once

Acceptance Criteria & Tests

1. Login as enterprise admin
2. Create fees at /admin/enterprise_fees
3. Add a calculator, see the correct field is display to enter the calculator's value
4. You only need to save once

Test with all calculators Repeat all with payment method Repeat all as super admin