Code Insights: Add dashboard count visibility info for the code insights edit UI

Created by: vovakulikov

Closes: https://github.com/sourcegraph/sourcegraph/issues/29943 Designs: Figma

Context

This PR adds a dashboard warning for the edit UI in case the current editable insight has been included in more than just one dashboard and editing of this insight will propagate to other dashboards.

Wildcard

This PR's design includes a Note-like component. Similar to wildcard '' component but not exactly the same (see designs, there is no icon for example). But still, it makes sense to have this Note component in the wildcard cause @AlicjaSuska also told that this Note component would be useful for other places in the app. And actually, we already have places like this with Note-like components.

So I added another variant note for the <Alert /> component @sourcegraph/frontend-platform see this commit https://github.com/sourcegraph/sourcegraph/pull/30892/commits/8dcde357da70ed970d6e1b458b4f71268ab79a67

Todo

• Extend Insight types with dashboardRefCount gql field
• Update Edit UI pages
• Add a new note variant to Alert component in the wildcard