FE iOS: Edit user details

[Radosław Bucki]

• Use GraphQL mutation with Authortization Bearer token header (Token should be saved in #7) according to this schema:

mutation {
  updateCustomer(
    input: {
      firstname: "Rob"
    }
  ) {
    customer {
      firstname
      lastname
      username
    }
  }
}

As input you can pass any customer data could be passed and should be updated then, if not passed data will not be changed