wip: template preview api

restapi/embedded_spec.go

restapi/handlers/account-template-preview.go

restapi/operations/logging.go

restapi/operations/prometheus.go

restapi/operations/rednerd_api.go

...perations/template_management/account_template_preview.go

...emplate_management/account_template_preview_parameters.go

...emplate_management/account_template_preview_prometheus.go

...template_management/account_template_preview_responses.go

...emplate_management/account_template_preview_urlbuilder.go

swagger.yaml