The old VideoForm and LivestreamForm were only reachable through a hidden `legacyEdit=true` query param on `/content/videos/:id` and `/content/livestreams/:id`. This removes that mode and deletes everything that was only reachable through it.

dashboard

Remove legacy VideoForm and LivestreamForm and the legacyEdit mode

Make Dashboard's UI locale list dynamic, similar to partnerplatform to allow automatic translations and listing

make dashboard own UI locale list dynamic

iOS users would sometimes experience server errors when viewing public news feed articles through the BNXTTV app, this should no longer happen.

Changelog.

Fix unhandled error on news feed articles