Convert all variant analysis commands to typed commands

[robertbrignull]

Please check each individual commit because I've done one commit per command.

This did actually find some places where our command arguments were incorrect. For the codeQL.monitorVariantAnalysis and codeQL.autoDownloadVariantAnalysisResult commands we were accepting a cancellation token parameter, but this parameter was not being passed in practice when we were invoking the commands. This meant the type of the argument was incorrect, but the commands already accounted this by checking if the token was undefined and ignoring it if so. Therefore this should be a behaviour-preserving change because the cancellation token was in fact always undefined already.

For codeQL.loadVariantAnalysisRepoResults I chose to give it a return type because this means we can use the existing loadResults method without having to define a new method that just ignores the return value. But I could do this if you think it would be better.

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[koesie10]

LGTM, I just have 1 very minor suggestion

[koesie10]

Can we make these type imports like all of the above imports just so we can see at once that there are no runtime circular dependencies?