feat(orm): Eloquent-style upsert() on the async Masonite ORM

[bedus-creation]

Summary

Adds a Laravel/Eloquent-style upsert() to the async Masonite ORM, exposed on both the Model (classmethod) and the AsyncQueryBuilder, mirroring how create() / bulk insert() are exposed today.

await Flight.upsert(
    [{"number": "AA1", "seats": 100}, {"number": "AA2", "seats": 80}],
    unique_by=["number"],
    update=["seats"],
)

• Inserts all rows in a single bulk statement (not a loop).
• On collision over the unique_by columns, UPDATEs only the columns in update.
• When update is omitted, all non-unique columns are updated (Laravel behaviour).
• Accepts a single dict or a list of dicts; unique_by / update accept a string or list.
• Returns the affected row count; returns 0 for empty input.

Dialect-specific SQL

Built with SQLAlchemy's dialect insert helpers so each driver gets the correct clause:

Driver	Generated clause
Postgres	INSERT ... ON CONFLICT (unique_by) DO UPDATE SET col = excluded.col
SQLite	INSERT ... ON CONFLICT (unique_by) DO UPDATE SET col = excluded.col
MySQL	INSERT ... ON DUPLICATE KEY UPDATE col = VALUES(col)

When the resolved update set is empty, it degrades to DO NOTHING (Postgres/SQLite) or a no-op key update (MySQL).

Implementation

• masoniteorm/query/upsert.py — build_upsert_statement() picks the dialect insert helper from the connection driver and builds one bulk statement over a lightweight sqlalchemy.table(...).
• QueryBuilder.upsert() — normalises rows to a shared, deterministic column set and runs values through the model's casters (consistent with existing insert paths), then executes the construct.
• Connection.execute_statement() — executes a SQLAlchemy core construct directly (commits when not inside a transaction), since upsert SQL is built with dialect helpers rather than the grammar.
• Model.upsert() — classmethod delegating to the builder.

Tests

• tests/masoniteorm/sqlite/builder/test_sqlite_builder_upsert.py — end-to-end against SQLite: insert-only, single dict, update-on-conflict without duplicating, update-list restriction, default (all non-unique) update, mixed insert+update in one call, empty input.
• tests/masoniteorm/test_upsert_statement.py — compiles the statement for Postgres, SQLite and MySQL and asserts the exact dialect clause + single bulk INSERT.

Full ORM suite (excluding live Postgres/MySQL): 386 passed, 7 skipped. New tests: 13 passed.