Current model UI improvement

[PaulCCCCCCH]

A few items on my mind:

Set Current Model Button

Currently Set Current Model button is only available under the edit action

This (at least to me) is a bit hard to find. Can we also place the button in the model list (e.g., next to Actions button) and make it more visible by users?

Current Model Sync Issue

Current Model card needs to refresh when we delete a model that's set as the current model.

Current Model Visibility

In model list, it will be easier for users to tell if we highlight the current model (e.g., with grey background, with a yellow star, etc.).

Also in the top bar (e.g., inside the red square), display the name of the current model, so that users always know what current model is.

[shuguang-lv]

@PaulCCCCCCH For Current Model Sync Issue, I think it's better to do all current model sync logic in backend when a model is deleted. Currently, the latest current model will be refetched using backend API when a model is deleted.