[10.x] Adds seeding within transaction

[DarkGhostHunter]

What?

This PR adds the ability to declare a seeder run inside a database transaction by using the WithDatabaseTransaction trait. The aim is to avoid incomplete or orphaned records when the seeder fails during development, forcing the developer to truncate the tables affected manually.

namespace Database\Seeders;

use Illuminate\Database\Seeder;
use Illuminate\Database\Console\Seeds\WithDatabaseTransaction;
use App\Models\Post;
use App\Models\Comment;

class CommentSeeder extends Seeder
{
    use WithDatabaseTransaction;

    public function run()
    {
        return Comment::factory(1000000)
                      ->sequence(fn() => ['post_id' => Post::inRandomOrder()->value('id')])
                      ->create();
    }
}

While this can be done manually using DB::transaction, the trait allows the developer to programmatically wrap it. For example, the developer can disable them for SQLite :memory: database, or for others RDMS on large lists of seeded records.

public function useDatabaseTransaction()
{
    $connection = Post::query()->getConnection();

    // Only run transactions when SQLite uses a file database for better performance.
    return $connection->getDriverName() === 'sqlite'
        && $connection->getConfig('database') !== ':memory:';
}

[taylorotwell]

Would rather just let developers have full control using DB::transaction.