2.7.0 Refactoring and relationships update fixes

What's Changed

• Feature/customizable request attributes by @CosmoV in #80
• Fix cascade changes by @CosmoV in #81
• Fix update relationship by @CosmoV in #82
• Sqla dl refactor by @CosmoV in #83
• Upgrade poetry config, disable package-mode since we're using hatchling by @mahenzon in #84
• bump version to 2.7.0 by @mahenzon in #86

Full Changelog: 2.6.0...2.7.0