Filter out legacy parties

[Bekabyx]

Asana

This work addresses a bug which Peter found where we're serving some legacy parties on the party lookup page. There's a little more detail on the Asana ticket, but essentially any party starting with "ynmp" is legacy.

There are two notable exceptions to this, and those are Speaker Seeking Re-election and Independent. This means the logic isn't quite as straightforward so I've had to import Q to get the filter just right 👌

To test locally:

• Open up the parties page locally
• Make sure Independent and Speaker seeking re-election are in the list
• "National Liberal Party, The Third Way" should NOT be in the list (gotcha: there is a party called National Liberal Party - True Liberalism. This one is supposed to be in the list.)

PR Checklist

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1. References a specific issue or if not, describes the bug or feature in detail
2. Note what card in Asana this work relates to
3. Instructions for how reviewers can test the code locally
4. Did I explain all possible solutions and why I chose the one I did?
5. Added any comments to make new functions clearer

[VirginiaDooley]

Tested locally 🚀