[vscode-apollo] Changing service in `apollo.config.js` requires a full VSCode restart

If you change the service name in `apollo.config.js` (and the corresponding API key in in `.env`), VSCode will report errors until you quit and re-open. It appears as though the schema is being fetched for the original service; I see this in an error message but don't want to paste a screenshot here because it's sensitive.

Start by locating the vscode-apollo handling for apollo.config.js and .env, then reproduce the issue by changing the service name and API key without restarting VSCode. Trace whether schema fetching continues to use the original service; done means the extension recognizes the changed configuration without requiring a full restart.

Written by the indexing model from the issue text.