* Use backend API route to fetch dynamic models
# Conflicts:
# app/components/chat/BaseChat.tsx
* Override ApiKeys if provided in frontend
* Remove obsolete artifact
* Transport api keys from client to server in header
* Cache static provider information
* Restore reading provider settings from cookie
* Reload only a single provider on api key change
* Transport apiKeys and providerSettings via cookies.
While doing this, introduce a simple helper function for cookies
