Move connections pane into core positron

[dfalbel]

Addresses #4874

Needs codicons from: https://github.com/posit-dev/positron-codicons/pull/6
Needs ark side: posit-dev/ark#589

This PR is an initial implementation of the connections pane into Positron core. It's still missing a lot of functionality, but will eventually be equivalent to the current positron-connections extension.

TODO:

• Workspace storage of previous connections
• Setting to opt-in for the new implementation
• Button to open data explorer for a Table or View
• Codicons for most common DB data types (schema, collections, etc) and for creating a new connection
• Review event listeners disposing
• Implement Python side of new GetMetadata RPC
• Implement refresh connections
• Display the field type
• Display the language for each connection
• Review error handling
• Fix smoke tests (smoke tests are passing locally)
• Fix integration tests
• Rename 'Connections Core' to just 'Connections'
• Support for the focus event

Demo:

Screen.Recording.2024-10-15.at.14.30.50.mov

Must be enabled with:

[softwarenerd]

Some nits. A couple of thoughts and a few questions.

[softwarenerd]

refreshConnectionEntries is not awaited? Makes me wonder if that's actually OK.

[dfalbel]

This starts an event that will eventually execute setItems because of the observer:

positron/src/vs/workbench/contrib/positronConnections/browser/positronConnections.tsx

Lines 78 to 80 in 09d74f5

	disposableStore.add(props.connectionsService.onDidChangeEntries((entries) => {
	setItems(entries);
	}));

It seems fine to not wait for it here in the useEffect() call. But maybe there's a better pattern for this, like useCallback()?

In 3c29b1b I added some error handling to make sure that the user is notified if something goes wrong before this event is called. Although there's already error handling at the RPC boundaries so we shoould display the entries marked with a special error icons if something goes wrong.

[softwarenerd]

Perhaps:

		return (
			<PositronConnectionsItem
				{...itemProps}
				selected={itemProps.id === selectedId}
				onSelectedHandler={() => setSelectedId(itemProps.id)}
				style={props.style}>
			</PositronConnectionsItem>
		);

Just a thought.

[dfalbel]

I tried this and it doesn't work. I have no idea why :S
I just changed to c34d6c7 which looks slightly better, I think!