We have the following controllers:

• PlaygroundController
• ConnectionController
• LanguageServerController
• StorageController
• ExplorerController
• ExplorerTreeController
• ParticipantController
• EditorsController
• WebviewController
• DataBrowsingController
• MCPController

A few of these (ConnectionController, LanguageServerControllerExplorerTreeController, StorageController) are considered "at the top" and a bunch of others use them.

Then the only existing exceptions before we came along were ExplorerController using ExplorerTreeController and EditorsController using PlaygroundController.

Every other time different controllers need to use each other they go through the vscode commands.

But then we (mostly me) added EditorsController, PlaygroundController and ExplorerController as direct dependencies of DataBrowsingController. Probably because no one was around to tell us that was a bad idea.

Now I want a playground to sometimes open a data browsing view and then we have a circular dependency unless we go through a vscode command. But we should probably already be doing that in data browsing controller.

So let's clean that up.