Add support for resource attribute assignment during object initialzation

[brndnblck]

Changes should be made in TwitterAds::DSL and applied globally.

Should allow syntax like this:

# create your campaign
attributes = {
  funding_instrument_id: account.funding_instruments.first.id,
  daily_budget_amount_local_micro: 1_000_000,
  name: 'my first campaign',
  paused: true,
  start_time: Time.now.utc
}

campaign = TwitterAds::Campaign.new(account, attributes).save

It should not allow setting read-only fields, derived fields or undefined properties.