(cherry picked from commit 9d3475d4)

Correctly use the Logger.exception method to capture exception backtraces if datadog timing logging fails

Only initialize formatters once, so that datadog is only initialized once, no matter how many plays are run

# The first commit's message is:

Pass playbook_timestamp into Formatters directly, rather than pulling it from callback_module

# The 2nd commit message will be skipped:

#	fixup! Pass playbook_timestamp into Formatters directly, rather than pulling it from callback_module