with items in task-machine concurrency

[jlin21]

• should with_items be evaluated in plan in the beginning and repopulated in the task list
• should with_items be evaluated as it appears then added to the task list
• evaluation can mean two things. create separate subtasks and have it rendered with both register and vars map, or create separate subtasks and not have it rendered.
• It will require string parsing to only evaluate {{ item }} and not {{ vars.* }}
• {{ vars.current_hostname }} will not work with current with_items implementation

[jlin21]

Current implementation - isolate {{ item }}, render and replace so {{ vars.* }} won't be affected. This reduces the need to change alot of other functions, and can be done before a plan is executed.