divergent_priors: Fix divergent_priors task

divergent_priors: Fix divergent_priors task

Flake8 fixes
Use new set_recovery_delay admin socket command
Fix bad value set for filestore_blackhole
Make sure log trims and only require 100 objects
Use kick_recovery_wq to properly set osd_recovery_delay_start to 0
Write and remove divergent and verify removal was undone
Fix to make compatible with wip-10809-11135-10290
Make sure to set_recovery_delay in a non-racey way (while osd running but down)
Leave divergent "in" so its PGs aren't treated as strays
Add yaml file to run the divergent_priors task

Signed-off-by: David Zafman <dzafman@redhat.com>