public / sequelize

When entities in a HABTM relationship can be joined more than once, we
need to rely on more than the resulting length for verification of
presence.

This was broken by:
https://github.com/sequelize/sequelize/commit/88a340dacec0b1b27d4f67866e2b416482ce7b85#diff-a140b60b6a99a8c69f4b5d0d1f1f2bfaR1964

So cc @u9r52sld 

We use sequelize with Redshift using the sequelize postgres dialect. It doesn't support the `standard_conforming_strings` option since it is based on an older version of postgres. Since https://github.com/sequelize/sequelize/commit/850c7fd04669e0fef9238b6dc4f8d6ee93ed71e9 was introduced, sequelize will try to set this option and fail, so I added a config option. 

Co-authored-by: Simon Schick <demwizzy@gmail.com>

Rename postgresql query debug namespace (mistake in #10630)