wire up loading of secretsmanager plugin, using renderer plugin as a model

pkg/plugins/manager/manager.go

@@ -23,6 +23,7 @@ var _ plugins.Client = (*PluginManager)(nil)
 var _ plugins.Store = (*PluginManager)(nil)
 var _ plugins.StaticRouteResolver = (*PluginManager)(nil)
 var _ plugins.RendererManager = (*PluginManager)(nil)
+var _ plugins.SecretsManagerManager = (*PluginManager)(nil)
 
 type PluginManager struct {
 	cfg             *plugins.Cfg
@@ -116,6 +117,16 @@ func (m *PluginManager) Renderer() *plugins.Plugin {
 	return nil
 }
 
+func (m *PluginManager) SecretsManager() *plugins.Plugin {
+	for _, p := range m.plugins() {
+		if p.IsSecretsManager() {
+			return p
+		}
+	}
+
+	return nil
+}
+
 func (m *PluginManager) Routes() []*plugins.StaticRoute {
 	staticRoutes := make([]*plugins.StaticRoute, 0)