Restore pre databases drop performance - add on_update on fields, possibility to name fks etc.

0.24.0

✨ Features

• Add on_update option to fields to customize SQL ON UPDATE behavior - thanks @vvanglro #1273
• Allow overriding auto-generated foreign key constraint names via fk_name parameter on ormar.ForeignKey, useful when the generated name exceeds the database's identifier length limit - thanks @nikelborm #849
• Forward autoincrement property from ormar field to the underlying SQLAlchemy column, enabling DDL with manually managed integer primary keys - thanks @smuething #674

🐛 Fixes

• Run standalone queries under AUTOCOMMIT isolation to remove the per-query BEGIN/COMMIT round-trip introduced in 0.22.0. Restores (and exceeds) 0.21-era performance on per-row CRUD and single-row reads while keeping explicit database.transaction() and savepoints working. bulk_update and iterate are internally wrapped in an explicit transaction so their batch-commit and server-side-cursor semantics are preserved #1629 #1635