Integrate the workspace trust feature

[aeisenberg]

This issue is about integrating the new workspace trust feature into vscode-codeql. See microsoft/vscode#120251 for the general feature.

Implementing this feature properly would be an effective fix for #509.

• Determine which settings require workspace trust. I found the following, but there may be more:
  • codeQL.cli.executablePath
  • codeQL.runningTests.additionalTestArguments
• Determine which commands require workspace trust
  • I don't think there are any, but worth taking a deeper look.