Fallback UI should show providers to be able to set

[JehandadK]

I was trying to add vertex_ai/claude-3-7 as a fallback to anthropic/claude-3-7-latest but it seems hard to identify from the UI whether it is a vertex ai model or anthropic. See below 👇🏼

Another possible feature request is that we want some models only to be available in fallbacks and not direct usage. Is that currently possible? If not what would the current team/model permission setup would like like to allow this?

I am thinking of something like model lists. Which can be selected and customized as opposed to all proxy model.