Switch processors from 'pre_processor' to 'processor' stage and other fixes

Overview

move processors from pre_processor to processor stage
added Pending status to the Order processor (it should be the default status)
use Payment.create or Contribution.create to complete a Contribution/Order
enforce order receive date in local timezone and ensure transaction date matches contribution receive date
Order/Payment/Participant fixes and workarounds
add support for Stripe add-on v1.4.9
support query event_id for generic Event form registrations
add cfc_participant_processor_is_registered filter