`#reset_counters` verifies counter names.

Closes #9724.

Raise an `ArgumentError` when the name of the counter does not
match an association name.
Merge pull request #9731 from senny/9724_argument_error_on_reset_counters

`#reset_counters` verifies counter names.
Warning removed unused variable task_name

warning: assigned but unused variable - task_name
Fix typos and improve docs a bit [ci skip]
Merge pull request #9732 from arunagw/warning_fix_unused_variable

Warning removed unused variable task_name