Add support for Virtual datasets & jinja2 templating for Superset

[hhhonzik]

Changes:

This adds a few additional lineage options to Superset db connection, mainly "virtual (SQL)" datasets with Jinja templating.

I've tested this thoroughly as a custom connector on our side and want to contribute to the rest of the project.

Type of change:

• Improvement

Checklist:

• I have read the CONTRIBUTING document.
• My PR title is Fixes <issue-number>: <short explanation>
• I have commented on my code, particularly in hard-to-understand areas.
• For JSON Schema changes: I updated the migration scripts or explained why it is not needed.

[github-actions]

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[github-actions]

The Python checkstyle failed.

Please run make py_format and py_format_check in the root of your repository and commit the changes to this PR.
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