with_items implementation for tasks

[madhurranjan]

[jlin21]

First pass of with_items will perform like ansible's. Register and using templates as a substitute for a list will not work yet

[jlin21]

To finish off this task, register support needs to be done. Solution:

• Add a register param in task.Run(...), if the param is not empty then use it as a list. This way it task.Run knows that it's a with_items call.
• Could also check the with_items field of the task. If the with_items field isn't null keep adding onto the register variable if it's present