fixes #7162 / BZ 1102763 - capsule - treat task as failed if sync times times out

Without this change, when an error (such as timeout) occurs attempting to
'capsule content synchronize' an environment, the synchronize task is reported
as successful.  E.g. from cli, this might look like:

hammer> capsule content synchronize --id 3 --environment-id 5
[.....................................................................] [100%]
Task 6c80df66-af10-44aa-9eca-c96992148811: success

With this change, if an error occurs that is reported back from pulp as
succeeded=false, we'll treat this as an error (because it is).  In
this scenario, the cli might look like:

hammer> capsule content synchronize --id 3 --environment-id 5
[..........................                                           ] [50%]
Task 2246bfb5-131f-4171-a7c3-6e16e3276ddd: error
Any reason you chose to create another class to house this?  Do you see it being used by other actions? (Versus just sticking it in the sync_node.rb class?)