Designs: https://www.figma.com/design/QE0mDJK9hlbPK9shnQCIbG/VS-CODE--DATA-BROWSING?node-id=1269-327074&t=XfRok1xj5ljskupq-4 

When the feature flag created in https://jira.mongodb.org/browse/VSCODE-721 is enabled, let's update the behavior that happens in the collection tree view to instead of having a dropdown with documents in the collection, show a tree view item that, when clicked, opens a web view. In the webview that it opens, app.tsx, we can then show a new component (also gated on the feature flag), that will be our entrypoint for the new view.  

Something we need to here also do is move the reset css call that happens here: https://github.com/mongodb-js/vscode/blob/c84482b4aee4832fe5654f89a73e100217842e29/src/views/webview-app/overview-page.tsx#L66 
To the top level app.tsx so this new view also gets it (we won't be showing the overview page). Looks like the Jira ticket in the TODO in that comment isn't right, I didn't find a ticket related for it though. 

The name of the tab should be the database.collection.