add metrics and usergroup subcommands

cli/functions/usergroups.go

@@ -0,0 +1,19 @@
+package functions
+
+import (
+	"net/http"
+
+	"github.com/gravitl/netmaker/models/promodels"
+)
+
+func GetUsergroups() *promodels.UserGroups {
+	return request[promodels.UserGroups](http.MethodGet, "/api/usergroups", nil)
+}
+
+func CreateUsergroup(usergroupName string) {
+	request[any](http.MethodPost, "/api/usergroups/"+usergroupName, nil)
+}
+
+func DeleteUsergroup(usergroupName string) {
+	request[any](http.MethodDelete, "/api/usergroups/"+usergroupName, nil)
+}