Changes to Get app service

the service/current_deployment_id response's property format changed from uuid to no format for status 200

added the optional property service/cron_concurrency to the response with the 200 status

added the optional property service/current_deployment_number to the response with the 200 status

added the optional property service/github_login to the response with the 200 status

added the optional property service/github_settings_url to the response with the 200 status

added the optional property service/github_status to the response with the 200 status

added the optional property service/max_previews to the response with the 200 status

added the optional property service/preview_count to the response with the 200 status

added the optional property service/previews_enabled to the response with the 200 status

added the optional property service/primary_domain to the response with the 200 status

added the optional property service/waiting_for_database to the response with the 200 status

endpoint added