Add upsert_multi

[feluelle]

Description

This is about enabling users to upsert multiple models/rows.

Changes

• add upsert_multi to FastCRUD using dialect-optimized sql
• add psycopg dependency for executing postgres statements via sqlalchemy
• add testcontainers to run tests in a ephemeral postgres container

closes: #110

Tests

• add postgres-specific upsert_multi test
• add sqlite-specific upsert_multi test
• add mysql-specific upsert_multi test

Checklist

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• I have added necessary documentation (if appropriate).
• I have added tests that cover my changes (if applicable).
• All new and existing tests passed.

[feluelle]

cc @JakNowy @igorbenav

[JakNowy]

This is great, I'm 100% for this postgresql approach in other cases.

[feluelle]

@JakNowy @igorbenav PTAL

[igorbenav]

Code looks good. Please add a db agnostic implementation as well and change the error for a warning, something like f"Upsert multi is not implemented for {db.bind.dialect.name}. Defaulting to slow db agnostic implementation."

[feluelle]

Sure, can do that.

[feluelle]

Hmm, I thought about it but instead added more support for sqlite and mysql/mariadb.

I think adding slow upsert using the current upsert method is not an option. It doesn't scale.

[igorbenav]

Nice one, thanks!