Allow the director to restart stateful nodes

[#42401241]

The director can now be configured to re-create stateful nodes when
performing a scan_and_fix. This option can be turned on by setting the
'auto_fix_stateful_nodes' setting to true inside the 'scan_and_fix'
key in the director configuration.

* Added resurrector integration tests.

* We now convert the job/index payload that we get from the health
  monitor into a nicer structure that is easier to work with in the rest
  of the code.

    { 'job1' => [0, 1], ... }  ==> [['job1', 0], ['job1', 1], ...]

* Added a helper to the integration sandbox that allows reconfiguration
  of the director in the middle of a test suite.
Only output the command run if it fails