fix: allow closing campaign after any finalized round

[ademolaomosanya]

pr fixes #143

the changes addresses:

• Campaign can be closed after the last round is finalized, even when that round is yes/no or rating (not only ranking) and If there’s still an active round, it must be finalized and also if there’s no active round but at least one finalized round, the campaign can be closed.
• “Close campaign” button is shown only when the campaign can be closed (canCloseCampaign), then success message is sent (“Campaign closed.”) after a successful close.
• Fixed template typo: rroundResults → roundResults so the cancelled-tasks value renders and the Vue warning goes away.

BEFORE

AFTER