Description of problem: We need to update the migration workflow to implement the warm migration specific steps. Initially, the workflow has been implemented as an Automate state machine. This becomes more complex to maintain, because Automate is not known to many ManageIQ developers. And we already use a Job to control the throttling. So, we will move everything from Automate to InfraConversionJob. For cold migration, the migration should be transparent, so we'll focus on non-regression tests. For warm migration, we need to implement new states, so they will require new tests. The goal of this BZ is to track the effort to migrate the workflow from Automate to InfraConversionJob. The implementation will be split in smaller BZs.