[go-server] move errMsg helpers to helpers file (OpenAPITools#20876)

Author: jarangutan

modules/openapi-generator/src/main/resources/go-server/helpers.mustache

@@ -15,6 +15,10 @@ import (
 	"time"
 )
 
+const errMsgRequiredMissing = "required parameter is missing"
+const errMsgMinValueConstraint = "provided parameter is not respecting minimum value constraint"
+const errMsgMaxValueConstraint = "provided parameter is not respecting maximum value constraint"
+
 // Response return a ImplResponse struct filled
 func Response(code int, body interface{}) ImplResponse {
 	return ImplResponse {

modules/openapi-generator/src/main/resources/go-server/routers.mustache

@@ -34,10 +34,6 @@ type Router interface {
 	Routes() Routes
 }
 
-const errMsgRequiredMissing = "required parameter is missing"
-const errMsgMinValueConstraint = "provided parameter is not respecting minimum value constraint"
-const errMsgMaxValueConstraint = "provided parameter is not respecting maximum value constraint"
-
 // NewRouter creates a new router for any number of api routers
 func NewRouter(routers ...Router) {{#routers}}{{#mux}}*mux.Router{{/mux}}{{#chi}}chi.Router{{/chi}}{{/routers}} {
 {{#routers}}