[ML] Allow a force delete for analytics jobs

[sophiec20]

For jobs which may have failed, there is currently a two step process to delete this job. First it must be force closed, then it can be deleted.

We should allow a force delete action so that:

• it allows a single step delete for failed jobs
• it matches anomaly and transform options
• we can stop in-progress analytics jobs quicker as we do not need to wait for any state to be saved as it is about to be deleted (note, this was true for anomaly detection)

[elasticmachine]

Pinging @elastic/ml-core (:ml)