Change dataflow and taint-tracking snippets to match the module-based API

[MathiasVP]

The snippets were expanding to the old class-based dataflow API which we don't want users to use anymore.

This PR updates those snippets to expand to the new module-based API:

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.

[robertbrignull]

One comment on whitespace in the snippet, but looks good to me either way.

[MathiasVP]

@robertbrignull I believe I've addressed all your comments (thanks for them!). Do you mind re-approving? 🙏

[robertbrignull]

Sure, can do so it's explicit 👍🏼

Though it isn't technically needed for this repo. The earlier review is still valid and allows merging.

[MathiasVP]

Sure, can do so it's explicit 👍🏼

Though it isn't technically needed for this repo. The earlier review is still valid and allows merging.

Oh, thank you! I missed what the page was actually telling me 😂

Anyway, I'm not in any rush to get this merged, so feel free to merge it whenever it fits you and your team best.