Rather than trying to enumerate tasks or track an ever changing cur_role
flag in PlayIterator, this change simply sets a flag on the last block in
the list of blocks returned by Role.compile(). The PlayIterator then checks
for that flag when the cur_block number is incremented, and marks the role
as complete if the given host had any tasks run in that role.
Fixes#20224
(cherry picked from commit cae682607c)
Rather than repeatedly searching for tasks by uuid via iterating over
all known blocks, cache the tasks when they are added to the PlayIterator
so the lookup becomes a simple key check in a dict.
* Unit tests exposed a problem where nested blocks did not correctly
hit rescue/always portions of parent blocks
* Cleaned up logic in PlayIterator
* Unfortunately fixing the above exposed a potential problem in the
block integration tests, where a failure in an "always" section may
always lead to a failed state and the termination of execution
beyond that point, so certain parts of the block integration test
were disabled.
Also making PlayContext a child class of the Playbook Base class,
which gives it access to all of the FieldAttribute code to ensure
field values are correctly typed after post_validation
Fixes#11381
