attach more info to an api-key

[ddragosd]

Currently when validating an api-key the Gateway retrieves some extra fields from Redis which are associated to it. ( see https://github.com/adobe-apiplatform/api-gateway-request-validation/blob/master/src/lua/api-gateway/validation/key/redisApiKeyValidator.lua#L62 )

These extra fields are used to decorate the request with more metadata about the application when making the request to the backends or they are used to send more info to analytics.

It would be nice to make the metadata more generic so that people can associate more fields with an application. OAuth token validator and User Profile validator are caching data in a JSON format in Redis and we could re-use the model for the API-KEY too.