add validation for string type: uuid

[GavinChenYan]

schema:
type:string
minLength: 1
format: uuid

we need add new format validation for uuid format string

[stevehu]

I found the following links and hope they are helpful.

json-schema-org/json-schema-spec#542

https://tools.ietf.org/html/rfc4122

https://stackoverflow.com/questions/50204588/how-to-define-uuid-property-in-json-schema-and-open-api-oas

[GavinChenYan]

user can use pattern to define the uuid format. But since uuid is validate format for openAPI. We should have validation for it. Added separate validator for it