[Filters] Validation based upon filter description

[jdeniau]

Hi,

If I am correct the filters are based upon OpenApi Parameter Object

They accept a required key, and nice things like enum, pattern, etc. but I don't think it's used by api-platform for now except for documentation and hydra:mapping generation.

Am I right or did I miss someting ?

If so, I will be pleased to open a PR with the start of query parameter validation.

Thank you