Move StoreKind under own StoreConfig configuration and rename to Engine (#1219)

* Move StoreKind under own StoreConfig configuration parameter

* Rename StoreKind option to Engine

* Rename StoreKind internal methods and types to Engine

* Add template engine value test

---------

Co-authored-by: Maycon Santos <mlsmaycon@gmail.com>

management/server/config.go

@@ -46,7 +46,7 @@ type Config struct {
 
 	PKCEAuthorizationFlow *PKCEAuthorizationFlow
 
-	StoreKind StoreKind
+	StoreConfig StoreConfig
 }
 
 // GetAuthAudiences returns the audience from the http config and device authorization flow config
@@ -138,6 +138,11 @@ type ProviderConfig struct {
 	RedirectURLs []string
 }
 
+// StoreConfig contains Store configuration
+type StoreConfig struct {
+	Engine StoreEngine
+}
+
 // validateURL validates input http url
 func validateURL(httpURL string) bool {
 	_, err := url.ParseRequestURI(httpURL)