Manageiq domain cleanup.

Remove unused lifecycle/discovery instances.
Remove extra best_fit methods and instances.
Modified cloud profile class schema to remove infra placement.
Modified cloud customizerequest method to be placeholder.
Modified cloud preprovision method to be placeholder.
Removed unused cloud provisioning vmprovision_template class.
Modified cloud vm provisioning statemachine to remove unused states.
Modified cloud vm retirement statemachine to remove unused states.
Modified cloud vm retirement statemachine method for new format.
Modified infra profile class schema to remove cloud availability_zone.
Modified service state machine to add addl pre and post states,
adjust field priority and messaging accordingly.