Describe the bug
When using remote development via the Remote-SSH extension, and adding a database with a zipped source archive to an open workspace/folder, VS Code shows an error and fails to add the source archive as a new workspace folder.

Error notification:

Extension 'CodeQL' failed to update workspace folders. Error: Workspace folders from different providers are not allowed in the same workspace.

To Reproduce

• Install VS Code on a local machine (I'm using 1.42 on macOS catalina).
• Install Remote - SSH and CodeQL extensions (extension 1.0.6, CLI 2.0.4).
• Command Palette > Remote-SSH: Connect to Host, then connect to a remote VM (I'm using Ubuntu 18.04).
• On the remote VM, create a parent directory, with a ql checkout as a child directory, and at least one child directory for custom queries.
• On the remote VM, create or place a CodeQL database with a zipped source archive.
• Open Folder > choose the parent folder on the remote machine.
• Add a CodeQL database from the Databases view, and select the database on the remote VM.

Expected behavior
The source archive should be added as a remote workspace folder (since it is also on the remote machine).