home add context for binding validate

[fanqingxuan]

because bind validator use the libaray of https://github.com/go-playground/validator, and user can add custom binding and validation by RegisterValidation, so user maybe query db、cache can some other component for their business，etc check unique from db, then need context parameter for query

bind valid interface original as

type StructValidator interface {
	ValidateStruct(any) error

hope as

type StructValidator interface {
	ValidateStruct(context.Context, any) error

[takanuva15]

Hi, this is something you should raise in the https://github.com/go-playground/validator repo since they control the signature for validation, not gin. (I would like this feature too to enable more advanced validations for requests)