[Accounts] Add Import Mapping Fix and add time helper

[phillipn]

There are two changes with this PR:

1. The Copy Field Mapping functionality is slightly broken.
   • Here is me trying to tell Matt that the mapping works fine - https://www.loom.com/share/af3b0158357b4bc7af7c92533ccf5971
   • Here is the resulting fix, with the code below - https://www.loom.com/share/18542b6879264580a1eb7ed6d62af44d
2. An extended label for an Import Action, that includes the time at which the file was uploaded, a nice to have