feat: add resource not found exception

[artengin]

Refs: #179

[artengin]

Cannot create Model:

Cannot create Repository:

Cannot create Service:

Cannot create Controller:

Cannot create Factory:

Cannot create Nova resource:
php artisan make:entity Post

php artisan make:entity Forum/Post

[artengin]

Currently, generating Requests, Resources, Migrations, Tests, and Seeders doesn’t verify whether the models exist. If this is a problem, we can go over the details, and I can revise the implementation.

[artengin]

I suggest adding checks before generation:

• For Requests, verify the existence of the Controller
• For Resources, verify the existence of the Controller
• For Migrations, verify the existence of the Model
• For Tests, verify the existence of both the Model and the Controller
• For Seeders, verify the existence of the Factory