feat: schedule objects for insert right after instantiation

[nikophil]

⚠️ merge #738 before

fixes #537
fixes #724

[simondaigre]

Minor comment : before this PR, when I use UserFactory::find(['customer' => $customer]); on Factory and when there is no results, the error was RuntimeException: Could not find "App\Entity\User" object.

And now it's RuntimeException: No "App\Entity\User" object found for "array"., which is unclear.

[nikophil]

@simondaigre is it related to this PR or Foundry 2? 🤔

if not related to this PR, but to foundry 2, could you please open another issue?

[kbond]

Nice solution!