Deduplicate filing types by unique filing type code, not EFSP code

[nonprofittechy]

See SuffolkLITLab/LITEFile#134

It looks like, from digging in efiling proxy server code, the only thing that matters is the filing code when the case is filed, so that internal identifier can be ignored.

(unless this changes upstream in EFilingProxyServer first)

[BryceStevenWilley]

Going to move this to the proxy server, it needs to be fixed there. If we don't just remove those dupes from the database entirely (I might, I'm so tired of this ridiculousness), at least our APIs shouldn't be returning dupes