Add WellArchitected service support in the endpoints package

[bigdatasourav]

Is your feature request related to a problem? Please describe. WellArchitected service support is not available in endpoints package

Describe the solution you'd like Please add support for WellArchitected service in the endpoints package. So that we can use functions like RegionsForService, endpoints.AwsPartition().Services()[serviceId].Regions() to find out the supported regions by the service.