Validate RTV "Started registration" value

[aaronschachter]

What's this PR do?

This pull request adds a check to only import a RTV record if its Started registration value is a date.

How should this be reviewed?

👀

Any background context you want to provide?

A great follow-up cleanup task would be to use this as the groundwork for better validation of the Phone number field before we import it. We use a very basic helper... but it still doesn't catch all variations

Relevant tickets

References Pivotal #175256802.

Checklist

• [x] This PR has been added to the relevant Pivotal card.
• [ ] Documentation added for new features/changed endpoints.
• [x] Added appropriate feature/unit tests.

[DFurnes]

A great follow-up cleanup task would be to use this as the groundwork for better validation of the Phone number field before we import it. We use a very basic helper... but it still doesn't catch all variations

Yeah, that would be great. I wonder what other fields Rock The Vote might give us weird/inconsistent data for too... 🤔