exception_to_status suggestions

[VincentLanglet]

Description
Hi @soyuka, I hope you're going well.

I just tried to use exception_to_status and had two suggestions. I wanted to get your opinion about it.

First, I find not friendly the fact we have to copy the defaut from ApiPlatform when we want to add an extra exception.
It implies:

• that we know the default value
• that if ApiPlatform add an extra value we update our config (or do not enjoy the default values)

I wonder if a better pattern for the option could be interesting.
Like adding another option exception_to_status_strategy: override/merge. To decide if we want to merge or override with the default value.

Secondly the context in which I wanted to add exception_to_status to the config was for

Doctrine\DBAL\Exception\UniqueConstraintViolationException

This could be consider as a 409 (I think ? Or a 422) ? Rather a 500.

In the same way OptimisticLockException is already mapped to a 409. WDYT ?

[soyuka]

Doctrine\DBAL\Exception\UniqueConstraintViolationException

Probably just a 422.

Its easier for us to replace values we do this for metadata everywhere we won't change the behavior for exception_to_status