Restarting vscode while the extension is starting up can remove databases.

[alexet]

Describe the bug Restarting the extension before all databases have been reloaded means we lose the databases that haven't been loaded yet.

Version

CodeQL extension version: 1.6.11 CodeQL CLI version: 2.10.3 Platform: linux x64

To reproduce

• Start vscode with the extension and add some large databases.
• Restart vscode.
• Close it while some but not all databases have been loaded.
• Reopen it and notice that the databases are missing.

Expected behavior

The databases that weren't loaded were loaded the next time.