[FEATURE]: Factories

[MatanYadaev]

Describe what you want

A factory API that allows creating testing data easily.

Example API inspired by Laravel Eloquent Factories:

// Generates 5 users in a 'verified' state with the password set as 'secret'.
// Each of these users will have 10 associated posts.
const users = await database
    .factory(users)
    .count(5)
    .state('verified')
    .has(database.factory(posts).count(10))
    .set({
        password: 'secret',
    });

[L-Mario564]

Closing in favor of #733.