use human-readable target names rather than target_id

[elray1]

currently, the drop-down menu for the target in the eval dashboard page is populated with the target_id for each target. Instead, we should use the more human-readable target_name from the target_metadata of the hub's tasks.json config file. We will need to pull this data in when the options file for predevals is created, see hubverse-org/hubPredEvalsData#21.