Clean up PlaybookExecutor logic for batches and errors
Clean up PlaybookExecutor logic for batches and errors

The calculation for max_fail_percentage was moved into the linear
strategy a while back, and works better there in the stategy layer
rather than at the PBE layer. This patch removes it from the PBE layer
and tweaks the logic controlling whether or not the next batch is run.

Fixes #15954

thaim/ansible,thaim/ansible