Add task in T3 to create candidate subdirectory when a candidate is "saved" and populate the appropriate level 2 data from the "operations" data

[danasimard]

This is mostly working (https://github.com/dsa110/dsa110-T3/commit/da204b20c5027e6c9f3440eef52f19eab16571e9) but there are only voltages for a few candidates. Should there be voltages for all of the candidates in the candidates directory?

[caseyjlaw]

This is working well.