Fixed clause_to_engine bug not finding the right db bind key

[ivan-gerov]

• fixes Bug with getting the correct bind when clause is a statement (like Insert) #1210

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• [ ] Add an entry in CHANGES.rst summarizing the change and linking to the issue.
• Add .. versionchanged:: entries in any relevant code docs.
• Run pre-commit hooks and fix any issues.
• Run pytest and tox, no tests failed.

[pamelafox]

@davidism I added the requested newlines. I also narrowed down the types and used isinstance checks to confirm the type of class containing the table. That was after digging through the SA code to determine where the "table" attribute came from. That might mean this fix won't work for other situations, but I haven't found other classes with a table attribute that seem like they'd come into play here. I also parameterized the test to confirm it works with 2.0 style.