Catch all exceptions in k8s submit_command()

[nemacysts]

It's entirely possible that creating a task_processing task (and/or submitting one) can result in an exception. At the moment, this results in the affected ActionRun getting stuck in the Starting state - but this is a lie and means that the normal monitoring/alerting on failed runs does not kick in.

[bobokun]

lgtm, if an exception does occur will it show up in META in tronweb? If not it might be useful to add the details there so users have a better understanding of why the job failed

[nemacysts]

lgtm, if an exception does occur will it show up in META in tronweb? If not it might be useful to add the details there so users have a better understanding of why the job failed

@bobokun not atm - I think that i could probably get it to show up there if i did something like task.log.exception(...) - but i'm a little wary of doing that in case there's something funky in creating the task that means we never even initialized the logger

[nemacysts]

(merging in master so that tests pass)