Customer page should not list all users in a drop down (too slow)

[simonredfern]

it should accept a username in a field

[sebtesobe]

Note (to whoever will implement this): The API call createCustomer requires a user id. If a username was provided, the API Manager would have to use the new call getUserByUsername to retrieve that id.

[sebtesobe]

Done, please check https://apimanagersandbox.openbankproject.com/customers/