Triage experiments should use list-making utility for temporal config

Timechop converts things it expects to be lists if they are not already. For example: `test_label_timespans: '1month'` to `['1month']`. Triage should do this when it reads in the temporal config or every time it uses the config components instead of only doing it in timechop. That way, the architect label generator will not fail when it splits `'1month'` into `['1', 'm', 'o', 'n', 't', 'h']`.

https://github.com/dssg/triage/blob/df6b427660b7b3a4ee549ccc42cfb7128ce214cd/src/triage/experiments/base.py#L418