fix: ask the CodeIgniter namespace confirmation once in make:cell and make:model

[paulbalandan]

Description
make:cell asked the CodeIgniter namespace confirmation twice, once for the class and once for the view. make:model --return entity asked it again when calling make:entity.

• AbstractGeneratorCommand now remembers the answer for the current generateClass() and reuses it for the views generated after it. The next generateClass() asks again.
• make:model calls make:entity with noInteractionOverride: true, so the entity only prints the warning. When the confirmation is declined, make:entity is skipped through the new protected isCodeIgniterNamespaceDeclined() hook.
• Non-interactive runs still print the warning and proceed, now once per class.

make:scaffold is unchanged and still asks once per sub-generator. Forcing its sub-generators non-interactive would also drop their own prompts, so an invalid --restful or --return value would fail instead of prompting for a valid one.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide