Competition Dump fixes

Fix memory issue from dumping competition with big datasets by only outputting keys to datasets (will address creating zip from stream, rather than having to load the entire dataset into memory in a separate issue: #370 )

fix incomplete dump by adding missing fields

• registration auto approve
• enable detailed results
• docker image
• queue (vhost)
• leaderboard: hidden
• column: hidden
• hide_output
• auto_migrate_to_this_phase
• description

fix terms not present

fix computation column indexes appearing as string rather than list