Fix bind reflection

[subnix]

Reflection is broken in extra binds, because of bind_key is not set for reflected tables.
Also sqlalchemy>=0.9.2 is required. So fix may be backported to 2.x branch if we can drop support for older versions.

• fixes Reflect not returning respective Bind #660

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.

[davidism]

Fixed in #1087. There is now a separate metadata per bind, which stores the bind key and tables. Reflection is done on each metadata, and does not need extra tracking in the table.